Yukina, an OL suffering from constipation, casually participates in a constipation treatment retreat she found online. However, it turns out to be an SM pervert trainer's enema-soaked anal torture exercise classroom. To improve constipation, one must train the muscles around the anus, the anal sphincter, and thus, the shy woman's asshole is forcibly trained! Expansion, foreign object enema, anal sex, and the female trainer's merciless torment. The woman's anus is relentlessly humiliated and teased to exhaustion, causing her to reach masochistic orgasms multiple times in the perverted enema play.
