[Kamatsuka (Kamatsuka)] Danshi ga Ore dake!? no Suieibu de Akogare no Senpai to Osananajimi ni Komon ni Shasei Kanri Sareteiru Koto ga Barete Shimatta Hon

The sole male member of a swim team falls under the wary control of three curvy, busty teammates—his childhood friend, his beloved senpai, and a manager who turns “ejaculation management” into a competitive training program. A sleek-bobbed instructor monitors his reactions with clinical precision while her long-haired and pixie-cut counterparts trade teasing commands, praise, and oral attention, each determined to expose how quickly his athletic composure can break. What begins as awkward squad supervision becomes a heated locker-room power game, their rivalry layering group pressure, endurance tests, and relentless control over whether he can remain composed.