Mitsura Mashiba

Mashiba is arrogant and status-conscious. Becoming a professional gives him something concrete to hold over insei who have not passed the exam, and he is willing to emphasize that distinction even when speaking to players whose actual strength may rival or exceed his own.

His confidence becomes especially abrasive around Isumi. Mashiba knows that Isumi is a formidable player, making his failure to pass the professional exam an easy target for taunting.

Mashiba's behavior also shows the difference between professional certification and absolute playing strength. He is talented enough to become a pro, but he is far from untouchable and can be unsettled when opponents refuse to accept the hierarchy he tries to impose socially.

Mashiba is a certified professional Go player and therefore possesses ability well above ordinary amateurs. He survives the insei system and successfully passes one of Japan's highly competitive professional examinations.

His later 2-dan rank shows continued professional participation. He also studies under Mizoguchi 9-dan, giving him access to structured instruction after leaving the insei ranks.

Mashiba's results nevertheless show that his professional status does not guarantee superiority over top insei. Strong players who narrowly missed qualification can still defeat him in direct competition.

Mashiba passes the professional examination alongside Akira and Tsujioka. He subsequently appears as one of the young professionals who have recently emerged from the insei system.

He faces Kuwabara in the Shinshodan Series and experiences firsthand the psychological pressure an established title holder can exert on a new professional.

Later, Mashiba competes against Shinichirou Isumi in the Young Lions Tournament. Isumi defeats him, and Mashiba responds by insulting Isumi over his repeated failure to pass the professional exam. Waya, angered by the insult, punches Mashiba.

Shinichirou Isumi is an insei Mashiba looks down on because Shinichirou Isumi has not yet become a professional. Isumi defeats Mashiba in the Young Lions Tournament despite that difference in status.

Yoshitaka Waya strongly dislikes Mashiba's arrogance. Yoshitaka Waya punches Mashiba after he insults Isumi following their game.

Akira Touya becomes a professional through the same examination cycle as Mashiba, although Akira's ability and career trajectory quickly distinguish him from the other successful candidates.

Hiroshi Mizoguchi is Mashiba's professional Go teacher.

Kuwabara faces Mashiba in the Shinshodan Series and uses his formidable experience and psychological presence against the young professional.