Yagi is the manager of the Kamogawa Gym and a contemporary of Miyata's father. His duties primarily consist of publicity and match booking, but he also takes part in managing the finances, selling merchandise, and occasionally even assists with the training now and then. He is a kind and friendly person, often adding ~kun to the end of the names of the Kamogawa gym members.
BackgroundYagi was originally a boxer for the Kamogawa Boxing Gym, having joined around the same time as Miyata's father. However, despite his passion, he lacked any natural talent to survive as a pro and suffered a string of losses.
Yagi is a master fisherman and whenever he fishes his personality changes (in the words of Miyata's father, "he gets the face of a demon"). He is so good in fact, that it has been said that he could become the World Champion of fishing. Additionally, numerous fishing ponds put up "No Yagi Allowed" signs after losing so many customers because Yagi was catching all the fish. He apparently had his fishing skills long before that, as Miyata's father learned the hard way while taking him fishing to cheer him up after a disappointing loss.
Ippo's Pro Debut
Yagi and Kamogawa, while watching a world match on the TV, talks about how they haven't raised a world champion since the gym opened. Yagi states that Takamura brought a newcomer. Yagi watches Makunouchi Ippo and Miyata Ichirou spar.
Makunouchi Ippo vs Oda Yusuke
Yagi and Kamogawa announces Ippo's opponent is Oda Yusuke. On the day of the match, Yagi notices that Ippo's name on his trunks is IPO instead of IPPO. Yagi stands at the ringside for Ippo's match. After Ippo's win, Yagi, Ippo, Takamura Mamoru, Kimura Tatsuya, and Aoki Masaru celebrates at the Sugar Ray.
Makunouchi Ippo vs Fujiwara Yoshio
Yagi acts as a cornerman in Ippo's match against Fujiwara Yoshio.
Rookie King Tournament - First Round: Makunouchi Ippo vs Jason Ozuma
Rookie King Tournament - Second Round: Makunouchi Ippo vs Kobashi Kenta
Japanese Middleweight Title - Takamura Mamoru vs Yajima Yoshiaki
Yagi acts as a cornerman in Takamura's match against Yajima Yoshiaki. Yagi celebrates Takamura's win with everyone.
Rookie King Tournament - Semi-final Round: Makunouchi Ippo vs Hayami Ryuuichi
Yagi acts as a cornerman in Ippo's match against Hayami Ryuuichi.
Rookie King Tournament - Final Round: Makunouchi Ippo vs Mashiba Ryou
Yagi acts as a cornerman in Ippo's match against Mashiba Ryou.
During a fishing trip aboard the Makunouchi Fishing Boat with the rest of the main cast he offered a friendly bet where everyone would pair up and see who could catch the most fish. He and Shinoda won by a landslide, and Takamura began training in fishing (in addition to his regular boxing schedule) in order to challenge him to a rematch. The rematch took place at one of the few fishing ponds that still welcomed Yagi. Although the end result was not shown, in the end the pond put up a "No Yagi or Takamura Allowed" sign.
During the Itagaki vs. Imai match, Yagi was asked by the coach to come up with a second encouragement pun after Shinoda couldn't think up another. The best he could do was pull Itagaki's Isu (Japanese for chair (or stool, in this case) away as he was returning to his corner and said Ima no ISU, Na~ISU (今のイス、ナ～イス, basically: This chair IS... nICE). Although the coach yelled at him for ruining the atmosphere, Takamura and the others found it hilarious and have been using it as a guts pose ever since.
Most Gym Members
Yagi has black short hair, large nose, dark eye color. He is seen always wearing eyeglasses.
Yagi possesses a gentle and friendly personality as a manager for the gym and its boxers. In contrast to Kamogawa's gruff and strict attitude, Yagi prefers to be more nurturing and optimistic when speaking to the boxers, showing genuine concern for their well-being. That said, it sometimes allows Takamura, Aoki and Kimura to take advantage of his meeker approach (often leading to Kamogawa stepping in with a swinging cane).
Despite being quite friendly as a boxing manager, he becomes incredibly competitive and cocky when it comes to sport fishing, more than willing to make bets (and fully aware that he will win them).
Like Kamogawa, he puts alot of trust in Ippo's ability to fight, though this is not without limits- if a bout has taken a turn for the worse and he feels that a boxer is at risk, he will readily suggest throwing in the towel.