Witness a moment of pure shock as a shy tennis club rookie watches his pristine girlfriend succumb to the advances of a dominant senior student! The narrator and Yuuhi—the beautiful and demure club manager—have maintained a sweet relationship so far; holding hands is thrilling enough without kissing. But during the team's retreat to a hot spring resort in Vietnam (or Asia), tradition dictates freshmen must massage their seniors. When the third-year senior strips off his towel for the routine back rub service on Yuuhi’s back—revealing an erection twice his own size—the narrator’s innocence begins to crumble.
The suspicion mounts quickly. Later that day near the bathroom entrance, they see them emerge together. Even though the senior insists it was just a massage while wearing a towel, the image sears into his mind. The next day confirms his fears: both are absent during practice, and he overhears another senior fetching condoms, hinting at further encounters! By the final night, the senior invites everyone to join him in 'playing' with another older woman, fully prepared for naked fun.
Devastated when he finds Yuuhi’s room in disarray—clothes scattered, tissues crumpled, and a distinct scent of semen hanging heavy in the air—the narrator frantically searches for answers. He checks the second-year's room, finding it empty, before finally reaching the third-year's quarters. As heart-stopping moans and wet flesh sounds echo from behind the door, he trembles to open it... revealing a scene that shatters his world!