Hiroshi Kizakura (黄桜 大,Kizakura Hiroshi) is a semi-recurring character in Hajime no Ippo.
Hiroshi is a close friend with Akamatsu Isamu and they both joined Kamogawa Boxing Gym after Aoki Masaru's first title match and made him not retire. These three together make the "Aoki Team" with their leader, Aoki. Hiroshi partakes in boxing training at times and helps Aoki at the Chūka Soba
His surname is Kizakura. In Japan, surnames are listed before given names.
Inspired by Aoki's JBC lightweight title match against Katsutaka Imae, Hiroshi and his friend, Akamatsu Isamu, encouraged their idol, Aoki to not retire when he was on the brink. Hiroshi and Isamu went with Aoki to the Kamogawa gym to be introduced to the gym members. As Hiroshi only follow Aoki's orders, he ignored Takamura Mamoru's order of getting him juice until Aoki told him to do it. While Hiroshi and Isamu were sitting around the gym, they were dragged into doing roadwork with Itagaki Manabu and Kimura Tatsuya. As Hiroshi and Isamu were having trouble running, they revealed how hard their past and only like the scent of Aoki because he wins without trying. When Aoki arrived to the group, Hiroshi and Isamu ran to him for comfort.
Hiroshi went to the Ryōgoku Kokugikan for Takamura's first WBC junior middleweight title defence against Larry Bernard. Hiroshi, Isamu, and Aoki were kicked out by the venue's staff due to them trying to cheer with instrument. In the anime, they did not play instruments, and Hiroshi and Isamu instead expressed how there is a smell of an easy win. After Takamura's win, Hiroshi ran away with Isamu and Aoki due to Aoki being blamed for Takamura getting hit after using the Look Away. Later, since Makunouchi Ippo needed help reviewing his fifth JBC featherweight title defence opponent, Sawamura Ryūhei, Hiroshi was one of the gym members to be called to Takamura's home to try and help Ippo. The event ended when Takamura got angry due to the large number of people in his room.
When Hiroshi dropped books next to Itagaki containing information about techniques that he and Isamu were gathering, Itagaki grabbed them as he was seeking information about the Dempsey Roll. While nothing was in it of useful information, when Hiroshi held out his hand to grab it from Itagaki, he startled Itagaki which sparked an idea to Itagaki about the Dempsey Roll's methodology and the books were thrown back to them. When Alexander Volg Zangief visited the Kamogawa gym, Hiroshi and Isamu had Volg polish the Statue of Takamura before getting scolded by Itagaki for it.
When the Kamogawa gym members' matches arrived, Hiroshi and Isamu went to the Yokohama Arena. While Kimura was fighting Eleki Battery, the two gave details about Kimura's situation throughout the match. They also brought Tomiko to Aoki's room in the venue to cheer him up. Hiroshi and Isamu wished Aoki good luck, however the two thought that even if he loses, remembering Takamura's bet of giving Aoki Papaya Dachiu's haircut if he loses, it would still be good. When Aoki's match against Papaya began, Hiroshi watched and cheered for Aoki. During the match, Hiroshi and Isamu could smell that Papaya has the same odour as Aoki. Hiroshi watched as Aoki's match ended in a draw. When Miyata Ichirō was having his fourth OPBF title defence against Medgoen Dachboy, Hiroshi and Isamu reported to Aoki that Miyata was still fighting in the fifth round. making Aoki leave his room to watch in the audience area.
After Takamura won against WBC middleweight champion David Eagle, Hiroshi followed everyone as they went to Takamura's house to make sure he went to sleep. Hiroshi and the others were thrown out as Takamura was unable to sleep with everyone watching.
When Aoki's hairstyle was forcefully cut by Takamura to be like Papaya's, Aoki gained popularity after using the new haircut, which looked like broccoli, to star in a commercial advertising broccoli as "Broccoman." To support Aoki, Hiroshi and Isamu cut their hair just like his and wore the trademark t-shirt. Hiroshi and Isamu arrived to the gym with Aoki to show Takamura how Aoki's Broccoman brand has grown, causing a fight between Aoki and Takamura. to see who is more popular.