Masamune Gotou is a high-ranking professional shogi player, holding the rank of 8-dan, and is known throughout the shogi world for his aggressive, intimidating style of play and his stern, physically imposing presence. He is in his thirties or forties and has a reputation for being rough and unpleasant, often creating a cold atmosphere in the shogi hall. Despite this harsh exterior, Gotou possesses a strict sense of honor in his approach to shogi; he refuses to use dishonorable tactics and has been shown offering sincere advice to earnest younger players while sharply silencing those who mock less accomplished opponents.

Gotou's personal life is marked by tragedy and compromise. His wife has been in a coma for years following an accident, leaving him in a lonely and effectively loveless marriage. This personal burden leads him into a long-term, complicated affair with Kyouko Kouda, the daughter of his former mentor, Ayumu Kouda, for whom Gotou was once a junior disciple. The affair stems from their shared connections in the shogi world and becomes a source of emotional turmoil for both parties, highlighting Gotou's struggle between personal desire and loyalty to his incapacitated wife.

In the story, Gotou initially functions as a supporting antagonist, particularly through his involvement with Kyouko. His relationship with the protagonist, Rei Kiriyama, begins on hostile terms after Gotou physically strikes Rei during a heated confrontation over Kyouko. Over time, however, Gotou's matches against Rei serve as pivotal moments of growth for the young player. Gotou becomes a formidable wall that Rei must overcome, and through these intense games, Rei gains a grudging respect for Gotou's dedication to shogi. Their dynamic evolves from outright hostility to a professional rivalry built on mutual acknowledgment of each other's strength.

Gotou also shares a significant professional rivalry with fellow 8-dan player Kai Shimada, and his interactions with the shogi master Yasuhiko Kouda are laced with tensions rooted in family ties and professional respect. Throughout the series, Gotou's character arc delves into themes of burden, honor, and isolation. He is portrayed as neither purely villainous nor wholly sympathetic but as a deeply flawed individual whose dedication to his craft and hidden vulnerabilities make him a complex figure within the competitive and emotionally layered world of professional shogi.