- 1 Background
- 2 History
- 2.1 Part I
- 2.2 Part II
- 2.2.1 Submarine Wars Arc
- 2.2.2 Dragon Slayer Arc
- 2.2.3 A Passing Point Arc
- 2.2.4 Spirit of a Weed Arc
- 2.2.5 Phantom Card Arc
- 2.2.6 Father's Back Arc
- 2.2.7 Chaos Arc
- 2.2.8 Seiken Arc
- 2.2.9 Operation World Domination Arc
- 2.2.10 Winner Takes All Arc
- 2.2.11 Red Lightning Arc
- 2.2.12 Second Coming of Death Arc
- 2.2.13 In the Jungle Arc
- 2.2.14 Chronos Arc
- 2.2.15 Blind Step Arc
- 2.2.16 Speed Zone Arc
- 2.2.17 Go to the World Arc
- 2.2.18 Battle of the Beasts Arc
- 2.2.19 Goals to Reach Arc
- 2.2.20 Seeking Heights Arc
- 2.2.21 10 Months in the Making Arc
- 2.3 Part III
- 3 Appearance
- 4 Personality
- 5 Gallery
- 6 Quotes
- 7 Trivia
- 8 References
As a child, she was a fan of Baldychu from the Pokamon series. When Kumi was 13 years old, she lost both of her parents in a car accident. Without her parents, Kumi and her brother would begin a life depending on each other. Kumi and Ryō were over their parents graves, Kumi was crying repeating,' What are we going to do?'. Ryō started his oaths.
Around middle school, whenever she was interested in a boy and they accompanied her home after school, they would run straight into her brother. After he stared them down, they would eventually lose to the pressure and run away, sometimes he would use violence. The pattern would repeat, causing her to never have a date.
In the anime, while Makunouchi Ippo was doing roadwork, he noticed Kumi riding a bicycle. He saw her again at the entrance of the Kōrakuen Hall when he and Takamura Mamoru were going to his pro test. Ippo saw her a third time while walking to school after his fight against Oda Yūsuke.
Kumi, during Miyata Ichirō's first match in the East Japan Rookie King Tournament against Takada Teruhiko, looked for her seat listed on the ticket and asked Ippo for help. At the time, Ippo had his pants unzipped accidentally, which surprised her. After Miyata won the match, Kumi wondered why "he" wants to box so much.
After Ippo's match against Hayami Ryūichi, Ippo returned to the Yamanka Bakery, where he met Kumi again. After finding out that Ippo was a boxer, with some trepidation, Kumi wished Ippo luck with it. Ippo left, thinking she was still a fan of Miyata's. When Mashiba Ryō was fighting against Miyata, she was watched the match, which Mashiba won in the end.
A few days after Miyata lost the match to Mashiba, Ippo visited the bakery again. He noticed Kumi was now sad, which Ippo believed she was depressed that Miyata lost. In an attempt to cheer her up, Ippo started mentioning that Miyata should have won the match if his opponent did not cheat. Kumi stopped Ippo, telling him to stop stating bad things about her brother, Mashiba, wondering how someone who doesn't know her brother make him out to be a villain.
When Kumi returned to her apartment with her brother, she began cooking for him. She mentioned Mashiba's boss (Tanaka) been helping them along, but Mashiba disagreed since he had a bad attitude where something bad would eventually happen, even though he had been working there for a year. Mashiba then told her that with boxing, he would be able to make money to stop her worries as he progressed to eventually the world championships. Kumi, however, did not care about being rich, she just could not take her brother feeling pain for her, fearing that one day her brother is going to breakdown.
During her brother's match against Ippo, Kumi hoped that Mashiba would not get seriously hurt in it. When Kumi saw Mashiba taking a lot of punches, she did not want to watch anymore and left the arena. Kumi then ran into Tanaka, who dragged her back in order to cheer for Mashiba. In the end, Mashiba lost the match.
At the dressing room, Kumi waited with Mashiba while he was resting. Kumi wanted Mashiba to stop boxing, but Mashiba realised he needed to start over again, since it is a world that draws him. After hearing that, Kumi decided to cheer Mashiba on. Later, Kumi had quit the bakery after Mashiba's match to work at the Tanaka Transportation with Mashiba.
Ippo was sent to the Kawai Hospital after his victory in the Class A Tournament against Alexander Volg Zangief. When he woke up, Kumi saw him and informed him that Mashiba had also won the Class A Tournament. Later, Kumi went to Ippo's celebration party where she was invited by Reiko, who was offered to come to the celebration party by Takamura, Kimura Tatsuya and Aoki Masaru. The group then played a game of bowling at the Rosa Bowl, with the first winner getting to pick first which girl they want to go out with. At the end of the game, Ippo went out with Kumi. After escorting her home, they had a short conversation before Ippo got scared of Mashiba and left.
After Mashiba became the JBC junior lightweight champion, Kumi called Ippo in order to help celebrate his win. When Ippo arrived, the apartment was dark, and only Mashiba was there. Kumi eventually arrived and celebrated the win with them. On the way home, Kumi walked Ippo to a taxi, Kumi mentioned that she would prepare a party for Ippo if he became champion.
After Kumi heard that Ippo lost the match against champion Date Eiji, Kumi called Ippo to ask him on a date since he was free. Ippo agreed to go on a date with her on Sunday. Ippo decided to take Kumi to the Kōrakuen Amusement Park. During the date, Kumi mentioned how her brother would scare a lot of boys that she liked and could never get a date. She also told Ippo that she was concerned about her brother boxing, she wanted to be able to help him in any way possible, where she started studying hard to become a nurse. During the haunted house ride, Kumi was left behind when Ippo thought he saw Ryō in it.
Kumi was asked by Tomiko to watch and cheer for Aoki, Kimura, and Takamura's matches with her. After Aoki and Kimura won, Kumi looked for Ippo. She became jealous when she saw Ippo talking to another girl. The next day, Kumi stopped by the Kamogawa Boxing Gym to celebrate everyone's win, but Aoki and Kimura were not there. Instead, Kumi followed Ippo doing his roadwork on a bike. She asked Ippo for an autograph since she wanted to be the first girl that gets one, and he agreed to it once they return to the gym. On the way back, she asked Ippo why he started boxing, but he did not answer. When Ippo arrived at the gym, he met Mari, who wanted to interview him. When Kumi saw Īmura Mari get an autograph from him, she got mad and left after leaving a "baka" sign outside the gym.
Kumi called Ippo to ask him something, which Ippo used as an opportunity to ask her about a date, which Kumi accepted. Ippo decided to take her to the Shimono Zoo. During the date, Kumi apologised for leaving the "baka" sign since she wanted to be the first to get Ippo's autograph. Kumi was then delighted to hear that Ippo would give her his first autograph as a JBC champion. After Ippo sent Kumi two tickets for his title match, Kumi and her brother went to the Kōrakuen Hall to watch the match. On the way to the seating area, Ryō bumped into Kimura. When a fight between the two was about to begin, Kumi held her brother back, apologising to Aoki, who was holding Kimura back. When Ippo's match against JBC champion Sendō began, Kumi watched with her brother, where Ippo was declared the winner and became the JBC champion. Kumi attended a birthday and victory party for Ippo following his win against Sendō at the Sugar Ray. Kumi didn't know it was Ippo's birthday, so she didn't bring a gift for him.
A few days later, Kumi called Ippo to meet up again. Kumi gave Ippo a new jogging suit as a late birthday present. Ippo gave her his autograph that he promised. Kumi mentioned she will hold his gift dear since she doesn't think she will be seeing him again, and takes off running. Ippo later found out that Kimura would be fighting her brother for the JBC title. Kumi met up with Ippo later where Ippo claimed that boxing is just a sport. Though she agreed, when Ippo encountered Kimura and then Ryō and they commented about them seeing each other, she ran away again as she believed they shouldn't meet for awhile. When Ryō's title defence arrived, Kumi watched with Tanaka where Ryō eventually won the match in the ninth round.
After finding out that Sanada was popular with the nurses where Kumi works, Ippo was pressured by his gym mates to confess to her, and ultimately almost did so, as when he was alone with Kumi in the snow. However, he could not confess, leaving her visibly upset as she was expecting it. She was then upset further when Ippo seemed to not care who she cheered for. After watching Ippo's title defence match against Sanada which ended in Ippo's victory, Kumi approached Ippo two days later. Kumi congratulated Ippo and claimed that she was alone in the audience and was cheering for Ippo.
Kumi went on a trip to the beach with Aoki, Tomiko, and Ippo. While there, they run into Takamura, Itagaki Manabu, Kimura, and Wanpo, who are in a training camp, along with Nekota Ginpachi and Hachi who were just visiting. That night, Kumi and Ippo were sharing a room at the hotel as planned by Aoki for the two to spend the night together. When Ippo and Kumi went out for some fresh air on the beach, Ippo told Kumi a ghost story, which scared her and brought her closer to Ippo. However, they ended up running into a shocking scene involving Takamura groping Tomiko next to Aoki near them when some fireworks explode, causing Ippo and Kumi to run to their hotel room.
Back in the hotel room after drinking alcohol, she began talking about her past with Ippo when they first met, drunkenly thinking it was at the Yamanaka Bakery, and how happy it made her when they met again at her hospital. Ippo then interrupted her to attempt to confess his love to her. However, Kumi fell asleep after Ippo's lengthy build up to when he claimed to love her.
On the final day of everyone's stay at the beach, Kumi continued to enjoy the beach while Aoki and Ippo try to get revenge on Takamura. That night at the beach, everyone but Takamura went to the beach to enjoy the fireworks while Takamura planned his revenge against them for having fun without him, by aiming fireworks at the group. When Takamura was spotted, he was talked into having fun with them after Kumi and everyone cheered for him to join them. After a while, the fireworks began to go off, making Kumi and everyone else run away from them.
When Ippo was at peak exhaustion and at the Swimming Club soaking, Kumi was tasked to keep an eye on him and to stop him from trying to work out. When Kumi was watching over Ippo, Itagaki and Itagaki Nanako arrived as well, with Kumi getting angry about Nanako's comments about Kumi and Ippo's relationship. Later, Kumi and Nanako talk about their brother being boxers, with Kumi being jealous about her positive attitude about it, and wondered what relationship Nanako was jealous about with her and Ippo. After Ippo was done, he goes out to eat with Kumi.
After Ippo's match against Shimabukuro Iwao, Nanako visited Ippo while he was resting from his match. When Kumi also entered his room, she stopped Nanako from her attempt to kiss Ippo. When asked why she came, Kumi mentioned she is here to take care of Ippo since she is a nurse. While she was arguing with Nanako, Īmura Mari entered the room and criticised them for being too loud. Mari and Nanako looked through a photo album of Ippo as a student, with Kumi not wanting to look without Ippo's permission. When Mari mentioned that based on how Kumi and Nanako are acting, they never made it far in their relationship with Ippo if they never been in his bedroom before and that she is interested in him, the three began to argue until Makunouchi Hiroko showed up. Hiroko mentioned that when Ippo is like this, she tries to let him sleep as peacefully as she can, which made Kumi, Nanako, and Mari feel guilty, and they decide to leave.
Kumi went to the Kōrakuen Hall and waited with Mashiba for Ippo to finish his weigh-in with Sawamura Ryūhei in order to give him lunch. When Ippo arrived, they walked to the amusement park to eat. Along the way, Mashiba noticed a parked motorcycle, wanting to ride it. Kumi got between him and the motorcycle to stop him, however, the motorcycle's owner, Sawamura, hit Kumi with a closed fist, barely hitting her, but leaving a mark on her face. Mashiba and Sawamura almost got into a fight before being stopped by Ippo, who requested for Kumi to come watch him fight against Sawamura as it would encourage him. While walking home, she was worried that there is something wrong with Ippo.
On the day of Ippo's match against Sawamura, Kumi went with Mashiba to the Kōrakuen Hall and watched the match that resulted in Ippo's victory. After the match, Kumi was asked to walk Ippo home. Along the way, Kumi asked Ippo why he started boxing, which he answered that he wanted to be strong. Kumi believed that since he is the JBC champion, he should know what it feels like now, but Ippo disagreed, since he hasn't caught up with someone, which Kumi realised he is talking about his father. Upon arrival to Ippo's home, Ippo was taken to his bed. While there, Kumi and Hiroko talked about how Ippo will never quit boxing and she learned about Ippo's father, Kazuo. Afterwards, Kumi walked home with Mashiba, telling him that she wants to visit their parents graves.
When Ippo was looking for help on learning about the detached retina disorder due to suspicions of Takamura having it, he asked Kumi for medical books on it. Kumi got a book from her hospital and gave it to Ippo, labelling what he wanted to know. After reading it, she asked Ippo if his eye is bothering him and was relieved when he said he was fine. Knowing that the detached retina is a major problem with boxers, she asked if it about one of Ippo's friends, but Ippo declined and asked her to keep it a secret.
During Itagaki's East Japan Rookie King Tournament semi-finals, Kumi helped Ippo and Itagaki train by timing their sprints. As Kumi and Ippo were about to make plans for Saturday since they were free, Nanako interrupted the two, claiming that she was free too. As they change the subject to talk about Itagaki's East Japan Rookie King Tournament instead, Itagaki was invited to go out with them Saturday, however, he wasn't in the mood. Later, Kumi received a phone call from Nanako at Ippo's house. Kumi was teased by her on the phone by revealing that her and Ippo were "going out" Saturday until Ippo grabbed the phone to explain that they were going to the Kōrakuen Hall to watch the qualifying match to see who Itagaki fights in the semi-finals, promising to go out with her next time. As she was bothered by the phone call, her brother asked for food. Kumi only glared at him, causing him to go get take-out instead.
Later, when her brother mentioned that he heard that Kumi was helping out with "the enemy's" training. Kumi wondered why he still holds a grudge against Ippo. She learned that Itagaki told him and noticed her brother's face being swollen.
Later, Kumi noticed Mashiba leaving in a hurry as he explained he was going to go clothes shopping with someone. Shocked, she called Ippo about it, thinking her brother has a date, which is something that has never happened before and wanted him to go with her to watch over her brother. As they watched, they were shocked to see it was Itagaki, and not a woman. They followed her brother and Itagaki as they went to the Hirosue. Kumi and Ippo overheard Itagaki and Mashiba's conversation, with Itagaki telling information about Kumi and Ippo to him, and Itagaki suggesting for Mashiba to relax on Kumi's relationship with Ippo to prevent her from rebelling. Afterwards, Ippo walked Kumi home, and when she got home, Mashiba doesn't ask her where she was and began laughing, which crept her out.
After Ippo's match against Karasawa Takuzō, Kumi found Ippo and Itagaki while their were training and was relieved to hear that Ippo was not hurt from his match against Karasawa. She gave Itagaki a drink that Mashiba uses when he is dieting. After asking Itagaki if Nanako was around, she was glad to learn that she wasn't. Itagaki revealed to them of Imai Kyōsuke's request to introduce Nanako to him if he wins, which Kumi realised that Ippo would never be able to challenge Mashiba for her. Kumi planned to go cheer with Ippo for Itagaki until Nanako approached them and hugged Ippo, making Kumi want Nanako to fall into the enemy Imai's hands.
When Itagaki and Imai's East Japan Rookie King Tournament finals arrived, Kumi went to the Kōrakuen Hall. She watched the match with the Itagaki family and Umezawa Masahiko while wearing a custom made victory headband made by Umezawa. Kumi cheered as Itagaki won and became the Eastern Rookie King by decision after six rounds. Due to his injuries, Itagaki was sent to the Kawai Hospital where Kumi works at.
Later, after Kumi confirmed that Itagaki's temperature was normal, she advised him to rest and not move around until his hand and foot better. After she left, she had to come back after Itagaki tried to escape the room, scolding him that he needs to rest, which he does.
A few days later, Kumi saw Itagaki off as he was about to leave the hospital, reminding him to rest now that he is released. When Imai offered to walk Nanako home, Kumi commented that Nanako should do it since they would make a good couple, making Nanako decline the offer. After Imai walked away determined to beat Itagaki in a rematch, Kumi mentioned to Nanako that men hate to admit they lost. Kumi remembered that Mashiba has a match coming up, thinking how boxers never seem to have time to relax.
After being invited by Aoki to go with Ippo to watch Miyata's fifth OPBF featherweight title defence against Che Jounbong, Kumi arrived to the Kōrakuen Hall and met up with Ippo. She congratulated him on his win against Take Keīchi, but was worried about the cuts on Ippo's face. After Mashiba approached the two and Kumi mentioned to Ippo that she didn't even tell him about her going to the Kōrakuen Hall, the three went inside the venue. After learning that Ippo's next opponent will be Miyata, she got scared since Miyata is an enemy who fought Mashiba. Kumi watched as Miyata defeats Che by knockout in the fourth round. Outside the venue, Kumi asked Ippo if he wants to go out for dinner. After he agreed, Mari and Fujii Minoru offered Ippo, Kumi, and Mashiba to go eat with them, with the editorial department paying for it. Ippo agreed to Mari and Fujii's offer after Mashiba forced him to, much to Kumi's dismay since she wanted to eat with Ippo alone.
After learning that Mashiba will be fighting Sawamura, Kumi and Ippo went to the Hirosue to eat. Kumi mentioned that he did not say that Mashiba would win when he was interviewed for the Monthly Boxing Fan magazine. While Kumi was not mad at Ippo, she was worried about Mashiba due to him starting to act like he used to be. Later, Kumi was warned by Mashiba to not come to his match against Sawamura. Despite the warning, Kumi went to the Kōrakuen Hall on the day of the match. She was reluctant to watch at first, but after Itagaki gave her his ticket so that she can sit next to Ippo, she decided to watch. During the sixth round, Kumi could not watch as Mashiba went wild and knocked Sawamura out of the ring while the referee had paused the match, causing Mashiba to lose by disqualification. When she left the venue, she told Ippo that she doesn't think that she will ever like boxing and hoped that Sawamura is okay.
Kumi attended a baseball game that Ippo, Itagaki, Aoki, and Takamura took part in for Kimura's local shopping district team. Since it didn't involve fighting and anyone getting hurt, Kumi enjoyed herself as she cheered. Along with Nekota and Nanako, Kumi cheered as Kimura's shopping district team won.
Kumi visited Ippo while he was fishing and asked if he wanted to go to the pool, as she knew that Ippo has free time since he just got done fighting Jimmy Sisphar. However, Ippo couldn't due to his injuries. As Kumi sat with him while he was fishing, Ippo apoligised when he started talking about boxing, but Kumi told him that she doesn't mind since she likes spending time with him. When Ippo asked how Mashiba was doing since he is still suspended, Kumi mentioned how tense he is because he wants a match. She added that she believes that she is the one who is tense since he always makes her worry when he fights, and doubts that he considers how she feels as she waits for him at home. After Ippo claimed that Mashiba cares about her, Kumi mentioned that Mashiba probably only thinks about winning during a match, whether he lives or dies for it rather than thinking about how Kumi feels. She claimed that she has gotten used to it, since she knows that boxers won't stop just because she says it's dangerous, and also knows that he will have to stop at some point. Kumi asked Ippo to make it back in one piece, just like she asks of her brother.
While Kumi and Ippo were eating at the Kahuna Pasta House, Ippo asked Kumi from a medical perspective if someone is able to extend and shrink back their arms, due to his next opponent, Malcolm Gedo, possibly doing so. Kumi doesn't think so, but she does know that some people can dislocate their joints easily, making their arm extend further than it normally would. Ippo wondered if it is possible for someone one to do it regularly, but Kumi thinks someone might be capable of doing it, however the stress over time would become a chronic problem. She was disappointed to learn that Ippo was asking because it is related to boxing. While Ippo was worried about not figuring out Gedo's "magic trick", Kumi was worried about how their relationship hasn't gotten any tighter in the years they spent together. By the time she got home, Kumi decided to not worry about it, as she prefers their slowly strengthening relationship. Upon entering her house, Mashiba complained how the sweater Kumi washed has gotten tighter, causing the two to argue.
Kumi visited the Makunouchi Fishing Boat to see Ippo. After Ippo and Itagaki finished their job with the boat, Kumi walked with Ippo. They talked about Mashiba's upcoming come-back match since his suspension is almost over. Kumi was worried ever since watching Mashiba fight against Sawamura, and does not think she can watch his next match alone. She was thankful when Ippo told her that he would watch with her, then got worried when he claimed that the come-back match is against the OPBF champion and that he would have a world title match soon enough. While Ippo tried to ease her worries by saying that Mashiba should be able to win without getting hurt, she was more worried about Mashiba's opponent. She thanked Ippo after noticing that he is trying to not make her worried, and the two planned to cheer for Mashba.
Kumi approached Ippo as he was training and reminded him that Mashiba's match is coming up as his suspension is almost over and was scared to go watch alone. Ippo claimed that he would go since Itagaki has a match before his, suggesting for both of them to cheer the two on. While Kumi was thinking of something else to talk about, she noticed cherry blossom petals falling, and thought that it is beautiful and romantic, wondering what Ippo thinks of them. When she asked what he was thinking about, she became flustered as he was thinking about boxing. As she began to leave, she ended up slipping on a sled near the hillside. Ippo tried to catch her, however, both fell onto the sled, causing the two to be face-to-face. As Ippo was about to kiss her, his head hit the ground as Kumi slid down the hill. Due to that incident, Kumi began to react erratically to to the words "slip" and "fall" since she believes that she one of those women who slips up at the most crucial moments and that she will not get another chance like that with Ippo.
On the day of Mashiba's OPBF lightweight title match against Aaron Domingo, Kumi went to the Kōrakuen Hall with Ippo. Before going in the venue, she became motivated when Ippo did not deny that she was his girlfriend when Saeki Takuma claimed that Ippo was with his girlfriend. Kumi watched with Ippo as Itagaki won against Kaonar Pachiyoso by knockout. Nanako, who sat next to the two, messed with Kumi by using the word "slip" in her sentences, which Kumi thinks she must have learned about her issue from Itagaki. When Mashiba's match was about to begin, Mashiba gets cheering from a cheer squad. As Ippo wondered who the people with the "Hell Society" headbands are, Kumi explained that Mashiba's boss, Tanaka, started a Mashiba fan club while Mashiba was on suspension. During Mashiba's match, Kumi was comforted by Ippo as she was worried when Mashiba fell and received fouls. After Mashiba won and became the OPBF lightweight champion by knockout in the tenth round, Mashiba threw his glove at Ippo since he was angry, thinking that Ippo was trying to take advantage of the situation. Kumi noticed that Mashiba seems to be different, as he has cheers from many people rather than him swearing to never rely on anyone or believe in anyone else, something that isolated him when fighting.
As Aoki was training for his Class A Tournament, Tomiko mentioned to Kumi how he has been acting like an animal. Kumi thought of Ippo as a herbivore, keeping to himself, while Tomiko saw Ippo as a cobra hiding in a turtle shell. Kumi claimed that he never seemed to go after things and act like an animal, wondering if she isn't appetising to him, however, Tomiko pointed out that she was just talking about the way he fights.
Kumi went to the Makunouchi Fishing Boat to hang out with Ippo, who had free time after winning against Wally.
Kumi was invited to an [[Nermina Park]amusement park]] by Ippo, who received free tickets from Kimura since he had extra. When Kumi and Ippo met at the park, they came across the groups Aoki and Tomiko, and Itagaki and Mari. Ippo tried to stop Aoki from spreading rumours of Kimura being an anime-loving paedophile after finding an anime DVD in his room, until Aoki called Kimura to show them his girlfriend. However, Kimura was near the group, not knowing they're there and told Aoki that he is was at the park and would show his girlfriend another time, as Kumi and the others see Kimura with a little girl. Aoki called the cops and had Kimura arrested.
Kumi and Mashiba arrived to the Ryōgoku Kokugikan to watch Ippo fight in his eighth JBC featherweight title defence match against Kojima Hisato. Outside the venue, Kumi and Mashiba came across Saeki Takuma, Date Eiji, Okita Keigo, and Sendō. The five boxers got into an argument until they were stopped by Kumi, who screamed at them to stop. Kumi went in the venue and watched Ippo's match against Kojima with Mashiba. Kumi watched as Ippo won by a one punch knockout in the first round, and Takamura's fourth WBC middleweight title defence match against Peter Rabbitson, which ended in Takamura winning by a one punch knock out in the final twelfth round.
After watching Takamura and Ippo defeat Rabbitson and Kojima respectively, Kumi went to the Mayweather Bar with Mashiba, Okita, Saeki, Sendō, and Date to celebrate Takamura and Ippo's victory. When Mashiba and Sendō began to argue, Kumi and Saeki tried to calm them down as Date figured that the two are angry about Takamura's poor performance. As everyone agreed with Date, the group complained about Takamura for his performance and his panda outfit until they notice that Takamura was in the bar with them the entire time. Since Takamura heard everything they said, he acted like he was going to leave before proclaiming that he blocked the door so they couldn't leave. Date's further provocations sparked a bar fight between the group and Takamura, which ended in all five boxers getting knocked out and Kumi having to put bandages on them. The next day, Kumi visited Ippo's room at the Makunouchi Fishing Boat after she heard from Itagaki that he was sick, but Ippo claimed that it was only a fever. Ippo mentioned that Kamogawa gave him some good advice about how violence is bad, which Kumi agreed.
After Aoki lost to Iga Shinobu in the Class A Tournament, he was sent to Kawai Hospital. At the hospital, Kumi informed everyone that he is in stable condition, and once his swelling and fever go down, he will be examined by a specialist and most likely be released.
At her house, Ippo came by to drop off extra fish that the customers at the Makunouchi Fishing Boat caught. Kumi invited Ippo inside to help her cook since Mashiba wasn't home yet. As Ippo taught her on how to get the scales off the fish, some of the scales kept hitting Ippo's face, which Kumi apologised for. Sitting in the living room while waiting for the food to cook, Kumi offered to replace Ippo's bandage on his eye since it was dirty. After she did it, she expressed how worried she gets even though she knows Ippo tries his best in boxing, and they almost kissed until Mashiba came home and informed her that the pot is able to boil over. When dinner was ready, Kumi ate with Ippo and Mashiba. When Mashiba learned that Ippo helped make it, he complained about the food and left the table, making Kumi angry as she thought it was good. After Mashiba criticised Ippo's reason for training to come home safely for his mother who waits at home for him and wants to be able to walk home using his two feet, Kumi backed Ippo, thinking that there is nothing wrong with that. When Ippo left, Kumi tried to hit Mashiba for ruining the mood.
After hearing Mashiba claimed that Ippo's match against Alfredo Gonzales ended with best knockout of Ippo's matches, she thought Ippo won until she read the paper, learning that he lost. When she went to the Makunouchi Fishing Boat to go see Ippo, Umezawa told her that Ippo was on a morning walk. She found Ippo and showed him the paper, which made him realise that he lost. As Kumi walked with Ippo to his house, she mentioned how anyone that cares about him would get worried after seeing his swollen face, asking why he can't quit boxing. After Ippo mentioned that he knows that boxing is dangerous, Kumi added that he is no longer the Japanese champion, so he has nothing to protect or any duty to keep on fighting. Ippo still was determined to return, claiming that he betrayed others expectations for a second time. Kumi questioned Ippo on his reason for boxing and becoming the world champion being to live up to everyone's expectations. Ippo mentioned that he knows, and doesn't want Hiroko to worry too much, so he claims that the next time he loses, he will retire and never fight in the ring again. Later, Kumi went to the Yokohama Arena to watch Mashiba's first OPBF lightweight title defence match against Romeo, which ended in Mashiba's victory by knockout.
While Kumi was with Ippo as he was fishing, Ippo told her about being in Takamura's failed parade after he unified the WBA and WBC middleweight titles, which made her laugh due to what happened during it. After Ippo mentioned how Yamaguchi Tomoko has been examining Takamura, leading Kumi to want to learn how to do massages. Ippo decided to let her meet Yamaguchi, however, when they get to the Yamaguchi Chiropractic, their trip was disrupted as a naked Takamura flies out the boarded window. Later, Kumi went to the Makunouchi Fishing Boat and fished until Ippo came home. Kumi patched Ippo's injuries on his head from the training he was doing and reminded him about his promise to retire if he loses next time.
During Ippo's one month ban from the Kamogawa gym and training due to suspicions of him being punch drunk, Kumi went bowling with him at the Funa Bowl. While bowling, Kumi was performing well, while Ippo got a lot of gutter balls. When Aoki, Kimura, Takamura, and Itagaki arrived, she got irritated since they ruined their time together. Later at the Kawai Hospital, after Ippo received good results on his brain scans, Kumi saw him off as he left the hospital, saddened that he has gone back to the ring again and was worried that he will continue until he can't go on.
At her house, Mashiba complained to Kumi about her cabbage roll dinner after she burnt it, believing that it is Ippo's fault since she was probably thinking about his upcoming return match against Antonio Guevara. When Mashiba mentioned that he will go watch the match, she requested for him to cheer him on for her since she has to work. After Kumi claimed it wouldn't be good if he loses, Mashiba told her that he would let her know if he wins, however, Kumi couldn't answer Mashiba when he asked if it would be good if he wins or loses. After Ippo's lost against Antonio, Kumi stopped by the Makunouchi Fishing Boat to check on him. As requested by Hiroko, Kumi stayed with Ippo while Hiroko leaves for work. After realising he is fine, she started crying, believing it might be for the best that he retires so he doesn't have to struggle and suffer anymore, wanting to always be by his side as she loves him. She fell asleep next to him. When the two woke up, Ippo was surprised to see Kumi next to him and leaves for fishing. Kumi and Hiroko talk about waiting and worrying about Mashiba and Ippo as boxers. Hiroko concluded that despite their worrying, the people they wait and worry for are on their own adventure, and that Ippo may just go back, make a fist, and go on a new adventure once he finds another reason to.
That night, Ippo walked Kumi home. During the walk, Kumi suggested Ippo a specialist who has a good reputation for treating patients in combat sports that will check him for Chronic Traumatic Encephalopathy, the clinical term for being punch drunk. Kumi mentioned that she wants to be there to help Ippo with everything in a tender moment that ended up getting ruined by Mashiba, who came to pick her up.
After watching a movie with Ippo, the two run into Mari, who was about to go to the Otowa gym to interview Imai, however she also wanted to ask Ippo a question. Kumi got in-between the two and asked for Mari to not talk about boxing to Ippo, however, Mari said that she wasn't asking her. Kumi explained that Ippo is doing his best to forget about boxing, however, Mari claimed that he can't forget about boxing and that there isn't a reason for him to force it. Kumi mentioned that Mari needs to think how Ippo must feel, but Mari countered by asking if she meant how she feels. When Mari suggested that Kumi might be getting into by being with him since she is a nurse, Kumi claimed that if anything happens, she is prepared to take care of Ippo, but she is glad that Ippo stopped boxing before it came to that, since it would be too much for her to take of both Ippo and Mashiba. Realising that Kumi is worried about taking care of both of them, Mari told Kumi that she would not talk about boxing since she likes her. Ippo wanted to know about what Mari wanted to ask him about, causing Mari to tell Kumi how dense Ippo is since Kumi was talking about looking after him long term, basically admitting that she wants to get married. Kumi asked Mari what she thinks about Ippo, and Mari answered that she loves him as a pro boxer as she walked away. Kumi walked home with Ippo.
When they get to the Makunouchi Fishing Boat, they discover that Hiroko has dinner made for them, and that Nanako helped make it. After getting in an argument with Nanako, Nanako wanted to spend time with Ippo like Kumi has, and asked what he wanted to do. Ippo claimed that he wants to help people and make his family business to be a success, but since so many people have supported him for so long, he wants to give something back somehow, which Kumi thought was nice. After Nanako kept talking about boxing, Kumi became irritated and wanted her to stop, as she feared that it will remind Ippo of it and drag him back to it. When Ippo asked Hiroko if she thinks he has changed and she claimed that she wasn't sure, as she only cared about him making it back safe in one piece, Kumi agreed, and committed herself to get rid of anyone and anything that tries to get Ippo back into boxing. When Shinoda came by to visit and asked Ippo to return to the ring, Kumi yelled at him, causing him to get scared. After Shinoda explained that he wanted Ippo to become a second for the Kamogawa gym, Kumi argued that he is trying to get Ippo to go back into boxing little-by-little, starting with him becoming a second. Upon further explanation that he is requesting Ippo's help because of Kamogawa being in the hospital, Ippo decided that he would think about it. After Shinoda left, Kumi and Nanako walk home together.
The next day, Kumi visited Ippo while he was fishing. She asked him about Kamogawa, which Ippo claimed that Kamogawa already left the hospital, and he is resting at home now so he didn't get the chance to meet him and was worried, wanting to see him to feel better. Kumi told Ippo that he wants to see him to make Kamogawa feel better, and help his friends at the gym so that Kamogawa can rest easy. Ippo claimed that he will be going back to boxing as a second, which caused Kumi to get upset, however, she told him that she will believe in him and that she believed that Ippo will never use his fists in the ring ever again.
Two days day after Ippo saw Miyata win his match, Kumi helped Ippo, who was out fishing. While Kumi was becoming better at fishing, Ippo believed he's not getting better at being a second, despite all three matches being wins. When Ippo said he saw Miyata's match two days ago, Kumi became scared, as she hears Miyata's name from both Ippo and her brother all the time and doesn't want Ippo drawn into boxing because of him. However, she was relieved when she discovered that that was not the case.
After slapping Aoki Taihei, Ippo shaved his head and, for atonement, trained Taihei and Kintarō Kaneda. When Ippo met with Kumi, he showed her his bald head, which reminded her of the "Baldichu" plush she had from the "Pokamon" series. Unable to resist, Kumi proceeded to kiss Ippo's bald head. Kumi stopped herself and glared at Taihei and Kintarō after she noticed them watching. Kumi told Taihei and Kintarō that the kiss didn't count and to erase it from there minds, scaring the two.
Kumi went to the Makunouchi Fishing Boat to visit Ippo when he returns from the boating trip. When she got there, she found Taihei and Kintarō, who informed her that Ippo has not returned yet. She asked the duo if Ippo is being a good teacher and if their practises involve sparring. After they claim that they have only been running, Kumi was glad, mentioning that Ippo is punch drunk, and wanting the two to stop him from doing anything dangerous. When Taihei and Kintarō mentioned that Miyata came to visit Ippo recently, Kumi panicked, thinking that Miyata is trying to tempt Ippo back to boxing before remembering that Ippo's heart did not waver the last time they met. She told the two to report to her the next time something like that happens again. She became cheerful once she sees Ippo returning from the boat. Later at the Kawai Hospital, a patient asked Kumi if she was worried about Mashiba fighting in his match against Iga, however, she advised for him to worry about himself rather than others. Tomiko informed her that she heard from Aoki that Mashiba got a down in the first round and asked if she was worried. Kumi told her that she is used to waiting and knows that there are great people with him.
When Kumi visited Ippo as he fished, Kumi found out from him that Sendō paid him a visit and that he had an encounter with Aikawa at his class reunion, who said that he hasn't changed at all, making Kumi feel gloomy. After freaking out while hearing Ippo explain his encounter with Aikawa, she felt better after Ippo revealed to her that he dropped Aikawa's note she gave him while shadowboxing.
When Ippo revealed to Kumi, Taihei, and Kintarō that he would go to Mexico alone for research, Taihei and Kintarō were excited for Ippo's motivation of meeting Sendō, resulting in a glare from Kumi, as that is why she has a bad feeling about Ippo's trip. When Ippo returned to Japan, Kumi received a Plue wrestling mask as a souvenir, which she liked.
After learning that Mashiba's next match is going to be him fighting in world title preliminary match, Kumi went to Ippo's fishing spot and informed him. After she mentioned that it would be a boxer named Juan Garcia as Mashiba's opponent, and learning that he was a former world champion and not someone easy like Mashiba said he was, she became worried about Mashiba coming home in pain due to him fighting strong opponents. Later, Kumi went to Mashiba's encouragement party at a public bar and invited Ippo as well. After the party, Kumi took Ippo home. During the walk, she told Ippo that the woman walking home with Mashiba is the daughter of the owner of Tanaka Transportation, Rie Tanaka, and that the company has people who were the first to accept Mashiba.
She is beautiful with short brown hair and dark coloured eyes, furthermore she isn't tall like her brother. In New Challenger, her body gains a paler/lighter skin tone.
In contrast to her brother, Mashiba Ryō, Kumi is quite cheerful and pretty. She first appears as a high school student and attracts the attention of many boys. However, her overprotective brother scares most of them off, resulting in her not having a boyfriend throughout her school years. She does not like boxing, but seems to have accepted it since the Ippo/Mashiba fight, which is also when she met Makunouchi Ippo. She disappeared for awhile afterwards but reappeared as a nurse after Ippo's fight with Volg Zangief. As a nurse, she often worries about Ippo and the other's wounds and even occasionally examines Ippo after his fights.
After meeting Ippo her feelings towards boxing have calmed considerably, but she still retains her basic feeling of wanting him and her brother to retire. She is often unable to cheer for even her brother and seems envious of Nanako, who can cheer for her own brother Itagaki quite easily. Also, after the Mashiba/Sawamura bout she told Ippo that she doesn't believe she will ever like boxing.
She and Ippo are in love with each other, but Ippo's clumsy personality and thick-headedness prevent their relationship from progressing at all, as well as the numerous intrusions from Nanako and Iimura Mari. Particularly, Nanako intentionally disrupts their time together, often claiming to be looking for Itagaki or just suddenly noticing them while walking by.
Although mostly different from her brother, when he went out to go clothes shopping with someone (Itagaki), she immediately called Ippo up to help her follow him, showing that she actually worries about him the same way he does for her. As she has become an adult she has also become a stronger woman, and has developed a habit of throwing objects at people (usually Mashiba) when her temper raises. She's arguably the only character in the entire series who has no reason to be afraid by her brother, and her comfort around him reflects this.
She has a hidden dark side that appears when someone gets in her way between Ippo. It makes her eyes look like her brother’s when she's angry. Kumi is able to give one menacing look to most people and they back down. She has done this to Taihei and Kintarō and they backed down immediately after seeing how evil she could be.
Main Article: Mashiba Kumi/Gallery
- "These are hot. They're fresh out the oven!" - Round 16, to Ippo during their second conversation at the Yamanaka Bakery
- "Is that why you get into the ring to box? Are you fighting to live up to everyone's expectations? Do you really think it's worth it? To become the World Champion for something like that?" - Round 1075, to Ippo after his loss to Alfredo Gonzales.
- "Even if you're not a boxer, even if something is wrong with you physically, I'll always be at your side." - Round 1207, thinking while watching Ippo sleep after his match with Antonio Guevara.
- According to the anime promotion site, Kumi (and Tomiko) works at Kawai Hospital (河合病院), which is a real hospital in Japan.
- Kumi's parents were killed in 1987, which would make her 13 years old at the time of their deaths.
- During the date to the Nermina Park, Kumi mentions she is a fan of anime.
- So far, Kumi has appeared on 3 manga covers - Volume 78, Volume 94(Background photo), and Volume 120.
- When Makunouchi Ippo meets Kumi the first time, his zipper is down. When Ippo meets her in the hospital after the Alexander Volg Zangief, his zipper is down again.
- Kumi has so far attended 5 boxing matches of Ippo, where he won.