Kazuhiro Yanaoka (柳岡 かずひろ, Yanaoka Kazuhiro) is a trainer at the Naniwa Boxing Club. He is Sendō Takeshi's trainer and second of both him and Hoshi Hiroyuki. He was the one who introduced Sendō to the boxing world.
He was a professional boxer in Japan. During his career, he was known to be a good fighter in the ring, in which eventually he became ranked first in the JBC, giving him the chance against the national champion of that time which was Miyata. He ended up losing fiercely in the seventh round after getting knocked down four times in the match. He later retired, remembering the feeling of being knocked down by him from time to time.
After retiring, he became a trainer at the Naniwa Boxing Club, in which he started training new boxers. He became a first class trainer and second whose skills were even recognised by Kamogawa Genji after his career.
Years later, a few of his trainees got beaten up by a delinquent named Sendō Takeshi, who Yanaoka almost knocked out. After Sendō took part in another rumble, Yanaoka turned him onto boxing as a way to find the strength he hungered for.
Looking for his boxer, Sendō Takeshi, Yanaoka discovered him looking at a video of Makunouchi Ippo's match against Mashiba Ryō. After hearing his boxer talk highly of Ippo, while claiming that the West Japan Rookie King Tournament was boring, he informed Sendō that Ippo is withdrawing due to injuries. This caused Sendō to go to Tokyo to talk to Ippo. After Sendō came back, he practised the Smash with Yanaoka. After the practise, a package came in from Ippo, with a note that claimed he may be able to go to Osaka. This caused Sendō to get fired up and continue practising with Yanaoka.
At the Osaka Prefectural Gymnasium on the day of the All Japan Rookie King Tournament, Yanaoka informed Sendō that Ippo got beaten by Komori. However, Sendō claimed that he would not underestimate him, but he will still win. When Sendō's match against Ippo began. Yanaoka was his second. Before the fourth round could start, Sendō sat unconscious, unable to get back up. Yanaoka realised that he was unconscious due to a hit to the temple, but was fighting because of the cheers. Sendō came back to consciousness and asked Yanaoka how he lost, but Yanaoka told him that it was a splendid fight.
After Date Eiji defeated Ippo and relinquished his belt, the two boxers fighting for the title was Sendō and Alexander Volg Zangief. When the match began, Yanaoka was Sendō's second for the match. The result of the match ended with Sendō winning by decision and becoming the JBC featherweight champion.
Yanaoka was one of Sendō's seconds in his first title defence against Saeki Takuma where Sendō won by knockout in the first round.
At the ring when Sendō's second title defence against Shigeta Akira was about to begin, Yanaoka warned Sendō about Shigeta's southpaw abilities. After the first round did not go into Sendō's favour, he told him to calm down and warned Sendō to be careful as Shigeta researched him. After the second round, Yanaoka was shocked when he discovered that Shigeta must had been a right-handed fighter before becoming a southpaw, but figured it was useless to inform Sendō about it as he is now a southpaw. Sendō then won and defended his title against Shigeta after using his speed he gained though Yanaoka's training method of using ankle weights in the third round. Later, at the Naniwa Boxing Club, Sendō entered and Yanaoka informed him that his training partners had arrived. While Sendō sparred against three sparring partners of a higher weight class, Yanaoka spoke with the Tokyo reporter Īmura Mari. When she mentioned the Dempsey Roll, Yanaoka claimed that they had no tactics against the Dempsey Roll. Noticing how Mari became shocked at witnessing Sendō sparring, Yanaoka told her he is different now and that he was thankful to Ippo and Volg for teaching them how brawl boxing was limited and the reason why he lost in close-ranged combat. Yanaoka figured that the key of Sendō's evolution would be weight shifting, so he had Sendō run and train his lower body. Yanaoka then revealed to her that the match would be a head-on duel, with Sendō taking on the Dempsey Roll and stay standing.
The day before the match, Yanaoka went with Sendō to the Kōrakuen Hall for the weight check. The next day, Yanaoka was Sendō's chief second for his title defence match against Ippo. After the fourth round, Sendō told Yanaoka that, just as Yanaoka kept his promise, he would prove to Yanaoka that he is Japan's greatest. When round five began, Yanaoka recalled his meeting with Sendō where he found him beating his students in the street and later joined the so he could take him to the Japan's strongest man to prove he is Japan's greatest. Eventually, Sendō lost against Ippo in the seventh round, losing his title. On a train to Osaka, Sendō explained to Yanaoka how he was afraid of going into the other car where his fans were as he felt as if he broke his promise to them. Yanaoka told Sendō to go back to his seat, however, when Yanaoka walked to tell him that, he triggered the automatic door, revealing Sendō to the next car where his fans are.
Yanaoka was Sendō's second for his come-back match since his loss against Ippo. After Sendō won, Yanaoka let him know that Ippo came to see him while in the changing room. While Ippo and Sendō talked outside the Osaka Prefectural Gymnasium, Yanaoka went to get Sendō so that they can go to the victory party.
Yanaoka went to the Osaka Prefectural Gymnasium to be a second for Hoshi Hiroyuki's match against Bunsaku Krati and Sendō's match against Jose Ramirez. After being a second for Hoshi's match that ended in a knockout in the first round, Yanaoka was the chief second for Sendō's match. After the sixth round of Sendō having trouble against Ramirez' jab, Yanaoka told Sendō in the corner that Ramirez puts his whole shoulder into it when he punches, warning him that if he keeps expecting the same range as a Japanese boxer, he will keep getting hit. Later, he went to the Osaka Prefectural Gymnasium to be a second for Hoshi's match against Itagaki Manabu, where the match ended in Hoshi's defeat by knockout in the first round.
At the Naniwa Boxing Club, when Hoshi revealed to the gym that Sendō went out for a trip to take down boxers in his "beat-down list", Yanaoka scolded him for telling the gym a week after Sendō went off, knowing that he will cause trouble. After learning that Hoshi looked at the list and only saw drawing of cats, Yanaoka asked the Naniwa coach what they can do, however, the coach did not want to think about it, instead, he wanted the gym to pretend they never heard about it. Yanaoka wanted to not think about it also, however, he was worried about the boxers that will fight him, since Sendō is irritated as he is in line for a world title match, but doesn't know how long it will be. When Yanaoka went to the Kawahara gym looking for Sendō, he saw him being rude while declining to spar with Miyata Ichirō again, and smacked him on the head, offering the Kawahara gym to have him do anything the gym wants, including sparring. Yanaoka was surprised to see Miyata, who he hasn't seen in years.
Yanaoka and Miyata went to the Mayweather Bar to talk about their past, where Yanaoka was driven to defeat Miyata, who was deemed unrivalled throughout Japan, however, Miyata defeated Yanaoka in the seventh round by knockout. Miyata apologised to Yanaoka for not living up to his expectations as a boxer, but Yanaoka compared Ichirō to Miyata, claiming that Miyata will take the world in a different way by teaching his son use the same counter that he used to use. Miyata revealed to Yanaoka that Ichirō learned the counter himself at a young age, which Yanaoka did not believe. Yanaoka listened as Miyata told him the most important day of his life was when he saw Ichirō shadowboxing with movements he learned from memory of his father's boxing, making Miyata want to watch his son as his last hope. When Yanaoka mentioned to Miyata that regardless of how he did it, he taught Ichirō how to box, Miyata did not want to admit it and claimed that Yanaoka must be drunk.
When Sendō's match against Jose Nargo arrived, he went to the Yokohama Arena. Since Sendō and Mashiba Ryō shared their changing room, the two argued and injured each other while he and Mashiba's coach tried to hold them back. Yanaoka watched Mashiba's first OPBF lightweight title defence match against Romeo, which ended in Mashiba's victory. When Sendō argued with Mashiba again once he got back, getting hit with an uppercut, Yanaoka carried him out as it was time for his match. Yanaoka arrived to the ring as Sendō's match against Jose began to act as Sendō's chief second. The match ended in Sendō's victory by knockout in the eighth round. Once Yanaoka and Sendō got back, Mashiba and Sendō argued again, causing Yanaoka to have to hold him back once more until Takamura Mamoru, the WBC middleweight champion, and Richard Bison, the WBA middleweight champion's match began. After seeing Bison use the Hitman Style, Yanaoka explained to Mashiba, who did not know the popular user of the style, about Thomas Hearns. He watched as Takamura won by knockout in the sixth round.
At the Naniwa Boxing Club, when Sendō wanted the coach to hurry up with getting him set up with a match against Alfredo Gonzales, as he noted how a match with Alfredo would be the fastest way to the world title, Yanaoka claimed that the match would not be a guaranteed win.
When Sendō's match against Alfredo, where the winner would earn the right to challenge the WBA featherweight champion, Ricardo Martinez was coming up, Yanaoka travelled to Mexico with him, When Sendō's weigh-in arrived, Yanaoka went to the Arena México to attend it. Afterwards, Yanaoka went to eat with Sendō, along with Hoshi, Ippo, Milo Scamaras. He later went to the Lucha Lucha Gym and was shocked to see Sendō sparring with the retired Ippo, ordering Sendō to stop since he is supposed to look over Ippo. Yanaoka mentioned to Sendō how, from what he saw, Ippo seemed to have evolved, noting his increased step-in and hand speed. He added how accumulated damage symptoms he showed when he last sparred with Sendō can alleviate after some time away from the ring, however, if a boxer like Ippo can't return to the ring with half-hearted feelings, they need a motivation. As Sendō walked off, Ippo asked Yanaoka if his help was enough for him. Yanaoka thanked Ippo, believing that Sendō will show something good during the match. The next day, he went with Sendō to the Arena México to be his chief second when the match against Alfredo began. After the first round, Yanaoka stops Sendō's nose bleed and instructed him about the Mexican lefts and how he should view Alfredo as an upgraded version of everyone he fought thus far. After the second round, Yanaoka advised Sendō to remember the reason he came to Mexico.
During the third round as Sendō had trouble against Alfredo, Yanaoka told Hoshi how Alfredo is clearly better than Sendō, as his only two losses were against Ricardo and he won against Ippo who defeated Sendō twice, adding that Alfredo would be champion if it wasn't for Ricardo. Hoshi questioned Yanaoka on how he went with the match knowing there was no chance for winning, but Yanaoka prayed for Sendō to get stronger during the match. During the fourth round, the referee paused the match. As Sendō was getting angry since he is unable to understand the Spanish-speaking referee, Yanaoka informed Sendō that his taping on his glove is loose. The taping got fixed by Hoshi, who tried to do it slowly to buy time to get Sendō to recover, however, Ippo yelled out to not buy time, as it would only cool him down. The match ended in Sendō's victory by knockout in the fourth round. After leaving the ring, Yanaoka and the other staff took Sendō to the venue's doctor's office for his broken right fist before going back to the changing room to watch Ricardo's WBA featherweight title defence match against the former WBC featherweight champion, Billy McCallum. Yanaoka watched as the match ended in Ricardo's victory by knockout in the first round. Afterwards, Yanaoka and the rest of Sendō's group got ready to go back to Osaka, Japan.
Later, when Hoshi's JBC featherweight title match against champion Kyōsuke Imai arrived, Yanaoka went to the Kōrakuen Hall to be Hoshi's chief second. The match ended with Hoshi losing in the first round by knockout. Yanaoka left the ring with Hoshi as he was put on a stretcher. After Hoshi passed out and he heard Sendō being noisy due to learning that Ricardo is going to fight Wally instead of him, Yanaoka went to where Sendō was at and began telling him to be quiet. He informed Sendō that he knew that Ricardo was going to fight Wally instead of him since before Hoshi's match, believing that it is to let his right fist fully heal before they fight. Later at the Naniwa Boxing Club, after watching Mashiba's world title preliminary match against Juan Garcia on TV, Yanaoka discussed the upcoming match between Ricardo and Wally with the gym's coach and Sendō, thinking that while he can't see Ricardo losing, Wally is a wild card.
When Yanaoka and Sendō arrived to Mexico, they met Ippo at the airport. Yanaoka told Sendō and Ippo that Volg and Wally will need them to be sparring partners since they crushed the others already. Outside, they meet up with the Marakas Brothers, who began to drive them to their gym where Volg and Wally are. Along the way, Sendō asked why Volg and Wally can't spar each other, but Yanaoka explained that while Volg would be useful to spar against, Wally is too wild to spar with. Yanaoka was shocked as Milo was about hit a pedestrian in the middle of the road, however, the pedestrian jumped back and landed on the roof of the vehicle, and it was revealed to be Wally, who cheerfully greeted everyone. When everyone arrived to the Lucha Lucha gym, Yanaoka watched as the spar between Sendō and Wally began. After the spar ended, Ippo and Volg got ready to spar. Yanaoka watched as Ippo and Volg's spar began. The sparring was stopped by Sendō as Ippo was starting his Dempsey Roll since it was only supposed to be a "touch spar".
|?||LOSS||?-1-0||197?||Miyata Senior||Tokyo, Japan||7(10)||TKO||JBC Title Match|
Yanaoka has short black hair with multiple bags going over his forehead. He is never seen without his round silver frame eyeglasses. Yanaoka usually wears his gym's shirts and, at the ring, wears a red Dynamite Glove shirt.
- Although his given name wasn't revealed in the manga, some of the video games such as Hajime no Ippo: Fighting Souls lists his full name as "Yanaoka Kazuhiro".