Masahiko Umezawa, Wiki Ippo

Masahiko Umezawa (梅沢 正彦, Umezawa Masahiko) is a professional assistant manga artist and Ippo Makunouchi's best friend outside of the Kamogawa gym. After a day of school, Umezawa, along with his friends, Takemura and Matsuda catch up to fellow student, Ippo, and began insulting and beating him underneath a bridge. Trying to provoke a reaction from the submissive high-schooler, they are stopped by a jogging Mamoru Takamura, who scared them away by dodging their punches and stealing the buttons off

Hajime no Ippo / Characters - TV Tropes

List of Hajime no Ippo episodes - Wikipedia

Masahiko Umezawa, Wiki Ippo

Chapter 1434, Wiki Ippo

Hajime no Ippo: New Challenger, Wiki Ippo

Chapter 441, Wiki Ippo

Umezawa Masahiko

Chapter 505, Wiki Ippo

Hajime no Ippo: The Fighting! - Rising - Anime - AniDB