"What does it mean to be strong?"

Ippo Makunouchi (幕之内一歩, Makunouchi Ippo) is the eponymous protagonist of Hajime no Ippo. He is a trainer, and also a retired featherweight professional boxer from the Kamogawa Boxing Gym and a former reigning featherweight JBC champion.

Since that moment onwards, he has formed a rivalry with other boxers, such as Ichiro Miyata, Takeshi Sendo, Ryo Mashiba, a brotherly bond with his peers Mamoru Takamura, Masaru Aoki, Tatsuya Kimura, and a deep trust for his coach, Genji Kamogawa, whom he aims to become a renowned champion to honour the coach's teachings. After retiring from boxing, he has become a trainer, being a second for his gym mates while training Taihei Aoki and Kintaro Kaneda.

Source: https://ippo.fandom.com/wiki/Ippo_Makunouchi