Kinoshita Gym
- Kazuki Sanada (真田 一機, Sanada Kazuki?): Handsome and highly intelligent, Sanada's full-time job is as a doctor at the same hospital in which Kumi works. Before moving up to the Featherweight division, he had a very successful reign as the JBC Jr. Featherweight Champion, defending the title five times. He is the pupil of Genji Kamogawa's old nemesis, Hama Dankichi, and in a fight, he uses his immense knowledge of human physical capabilities to predict his opponents' moves. His specialties include two of Dankichi's inventions: the "Hien" (飛燕?) -- named after a model of highly maneuverable Japanese fight plane, it's an unpredictable left jab known in English as the Swallow—and the "Tsubame Gaeshi", a piercing double uppercut known in English as the Swallow's Return. After his failed attempt to obtain the Featherweight Championship from Ippo, he retires from boxing to continue his work as a doctor. Sanada's character is fairly reminiscent of mid-1980s boxer "The Fighting Physician" Dr. Terry Christle, who had been the Irish national Middleweight champion and chief sparring partner of Marvelous Marvin Hagler during his training for his super fight against Sugar Ray Leonard. Christle had earned his Ph.D at the Royal College of Surgeons in Ireland, but before embarking on a medical career had wanted to give boxing a try, ultimately retiring in 1987. At the time of his retirement, Sanada held a record of 13-2-1 with 9 knockouts
- Voiced by: Kōichi Yamadera
- Takuzo Karasawa (唐沢 拓三, Karasawa Takuzō?): Sanada's kōhai (後輩?). After Sanada's retirement from boxing, Karasawa wanted to bring glory back to their gym, and so challenged Ippo for the featherweight championship title. He planned to use his lightning-fast feet to evade the champion's punches and counter the Dempsey Roll, but was mercilessly KO'ed in the second round due to Ippo's choice to seal the Dempsey Roll and focus on a back-to-the-basics approach on boxing. Was the Rookie King the year before Itagaki and JBC Featherweight 7th Seed at the time he challenged Ippo. (v62 p185)
Read more about this topic: List Of Fighting Spirit Characters