Coach Nishio is the head baseball coach at Meisei High School in the anime Touch. He is a character defined by a sudden health crisis that becomes a catalyst for significant turmoil within the team. Physically, he is often depicted with facial hair, which is one of his most distinguishing visual traits.

The central event regarding Coach Nishio is his unexpected and extended hospitalization during the senior year of the Uesugi twins. This illness forces him to step away from his coaching duties for nearly an entire season, leaving the Meisei baseball team without its regular leader at a critical time. Before his absence, Nishio is responsible for appointing Eijiro Kashiwaba as the interim coach. He describes Kashiwaba to the school officials and players as a kind, gentle man who possesses a deep and genuine love for baseball. This description sets a clear expectation for the team, which makes the reality of Kashiwaba's harsh and authoritarian coaching style all the more shocking to the players, particularly to Tatsuya Uesugi and the team manager Minami Asakura.

Nishio's role in the story is primarily that of an off-screen instigator. His absence forces the team to confront a dangerous and manipulative figure. The stark contrast between his glowing recommendation of Kashiwaba and the interim coach's actual behavior becomes a major source of conflict and mystery that the main characters must unravel. The narrative reveals that Nishio’s recommendation may have been a mistake, confusing Eijiro with his more famous and genuinely personable older brother, Eiichiro Kashiwaba. This error highlights Nishio's lack of direct involvement during this tumultuous period, as he is absent while the team suffers under the very person he chose to lead them. Coach Nishio eventually recovers from his health issues and returns to resume his position as head coach after the interim coach has led the team for almost a full season. By the time of his return, the team has already been transformed by the intense, albeit problematic, training methods of his substitute. Key relationships for Nishio include his trust in Minami Asakura, who he leaves in charge, and his professional connection to the Kashiwaba family, which proves to be dangerously flawed. His development is minimal, as his character is more of a plot device whose absence and well-intentioned but incorrect judgment set the stage for crucial events. There are no notable athletic or coaching abilities detailed for Nishio beyond his standard duties as a high school baseball coach.