A widower at around 30 years old, Shigeharu is Goro's father, a kind, warm man that sets a wonderful example for his son. As a result of bad luck, he has suffered multiple injuries throughout his professional baseball career, but with great effort and determination, he always finds a way to keep playing.

In time, Shigeharu develops feelings for Goro's teacher and is close to marriage when he suffers a head injury as a result of a wild pitch by Joe Gibson. Though he completes the game and performs well, he dies the following morning in his home. He continues as Goro's inspiration and is mentioned many times throughout the series.