Kimihiro Tsutsui

Tsutsui is kind, cautious and earnest. He lacks the aggressive confidence of many stronger players and initially reassures himself by consulting Go books during games.

His insecurity does not diminish his enthusiasm. Tsutsui works hard to establish a club even when he is its only member, runs Go-related activities to attract attention and welcomes beginners who genuinely want to learn.

He gradually becomes more willing to trust his own judgment. Playing alongside stronger personalities such as Tetsuo Kaga and Hikaru pushes him away from dependence on books.

Tsutsui is an average school-level Go player rather than an insei-level competitor. His knowledge is stronger than his confidence, and he initially consults joseki and strategy books while playing.

His strongest area is yose, the endgame. Careful counting and endgame play allow him to recover points even after falling behind earlier in a match.

Tsutsui improves through tournament experience, but the widening difference between ordinary school Go and Hikaru's insei-level development eventually becomes unmistakable.

Tsutsui first encounters Hikaru while trying to attract interest in Go through puzzles. At the time, he needs additional members before Haze can participate properly in school tournaments.

Kaga and Hikaru eventually join him for a team competition, giving Tsutsui his first real Haze lineup. The following year he works to build a sustainable club and becomes involved in recruiting Yuuki Mitani.

When Hikaru decides to become an insei, Tsutsui is one of the Haze players he faces simultaneously to demonstrate how far he has progressed. The enormous difference confirms that Hikaru now needs stronger competition. Tsutsui later graduates, leaving behind the club he worked to establish.

Hikaru Shindou helps Tsutsui turn the Haze Go Club into a functioning team. Tsutsui supports Hikaru Shindou's early development even though Hikaru eventually progresses far beyond school-level competition.

Tetsuo Kaga initially treats Tsutsui and his Go Club dismissively, but Tetsuo Kaga eventually joins him in competition and helps him rely less heavily on books.

Yuuki Mitani becomes an important recruit for Tsutsui's later Haze team, although Tsutsui initially objects to Yuuki Mitani's dishonest behavior.

Akari Fujisaki joins the club Tsutsui founded and helps ensure it continues attracting students.