Hoshi Hyouma

Hoshi Hyouma is a sixth grade at the same school at Isamu and Moka. Hoshi is the son of a boxing coach who runs Star Gym and his older sister is a professional female boxer. Hoshi doesn't have much confidence in himself because of a boxing loss when he was younger and he feels that he is no good at boxing compared to his sister. (Source: Buyuden Wikia)