Nishi is Joe's best friend, sparring partner and later he also becomes Joe's trainer. He is a juvenile delinquent. He first meets Joe in a juvenile jail, where they fight each other and Joe defeats him. Nishi later meets Joe at the correction house where they become friends.
Nishi's personality changes drastically from an arrogant juvenile delinquent to calm worker at a grocery store. He takes a liking to boxing after watching Joe's match against Rikishi in the detention center.
When Joe comes back to Namida Bridge he is surprised to find Nishi at the Tange boxing gym, Nishi joins the gym to learn boxing and to continue being with Joe. Nishi is an averagely good boxer. He was the only useful sparring partner Joe had in the entire story. Nishi has a crush on Noriko Hayashi, who is the daughter of his boss at the grocery store.
~!Nishi injures his fist in a match and painfully decides to retire from boxing. In his retirement party he confesses that he will always be proud of dedicating his youth to boxing. Later, Nishi marries Noriko and becomes more dedicated to his work at the convenience store but he also continues to help Joe with his training and works in the corner during his matches.!~
