Kurotaki Buchou no Inokori Shidou

Kurotaki, the new captain of the swim club, is a strict and demanding senior who pushes her members to their limits. Rumors say that anyone summoned by her after practice quits within a week. When the protagonist is called to stay behind, he expects a harsh reprimand, but instead finds himself in an unexpected situation.

After grueling training sessions, he endures daily encounters with the captain, who uses him as her sexual partner. As the days pass, he struggles to keep up with both the physical demands of the sport and her relentless advances. Even after a break, the summons continue, leaving him wondering how long he can endure.