Ken Mayumura

Introduced in season 2, he is initially asked to teach Goro a lesson by Kaido's recruiter for rejecting Kaido during a middle school game between Kaido Unified, and East Mifune. This beating makes him the instant rival of Goro, even though he admires him for his confidence and straight forward attitude. His personality is very direct and to the point, often times coming off as cold. He appears to be in complete control of his emotions at all times, including when facing established and more experienced players.

His pre-game ritual of sitting in a bathroom stall while listening to music is seen by others as getting him in the right frame of mind to pitch, but in actuality he does it because he is anxious and helps him focus his anxiety. His goals are to achieve all possible individual achievements in Japanese Baseball before moving onto the Majors.