Manami Miyoshi is a former star player of the girls' water polo club at the high school central to the story. She is a university student who returns to the school to serve as a temporary assistant coach for the team. Her background as a skilled water polo player gives her a natural authority in the sport, and she volunteers her time to help the current members improve. Personality-wise, Miyoshi is playful and forward, with a pronounced tendency to tease others in a flirtatious manner. She is especially drawn to virgins and often directs her seductive advances toward Yohei Hamaji, finding his embarrassed and flustered reactions highly entertaining. This teasing behavior is a key part of her interactions and defines much of her role in the narrative. Her primary motivation appears to be personal amusement and the pursuit of physical intimacy, particularly with inexperienced partners, rather than any deeper emotional connection. In the story, she functions as a supporting character who adds comedic and risqué elements through her interactions with the main cast, especially Hamaji. Her most notable relationship is with Hamaji, whom she persistently targets with her advances, while he remains largely oblivious or overwhelmed by her attention. There is limited information about her development over the course of the series, as her role primarily revolves around her established personality traits and her coaching duties. Her notable ability lies in her water polo skills, which she leverages as a coach to guide the team, though her expertise is secondary to her comedic role in the series.