Students in competitive swimsuits at the public swimming pool have erect nipples and are being sexually assaulted with penises, resulting in nipple stimulation and climax training. (Ono Rikka, MIDV-843)

Rikka goes to the swimming class at the community pool with her mother. She always had confidence in the instructor's serious guidance... However, the unintentional glimpse of her developing nipples through her swimsuit aroused the perverted instructor, beginning his lewd nipple-development days... Stimulating her sensitive nipples on the smooth surface of the swimsuit quickly made her more sensitive and wanton, leading to frenzied orgasms. The swimsuit and training became increasingly intense, eventually culminating in ejaculation inside her...