I was perfect in both academics and clubs, and the most popular student, but after one bout of incontinence, I became the class's sex slave. (Nanamori Riri, SONE-619)

The beautiful and talented Nanamori Riri, the most popular girl in school, is about to embark on her long-awaited school trip, gathering with her classmates to prepare. Among them is another girl, Sachi, a close friend and relative. However, the boys only talk about Nanamori Riri, and Sachi is always used as a tool. Growing increasingly jealous, Sachi finally tampers with Nanamori Riri's drink, putting a diuretic in it. The urge to urinate intensifies, and she rushes to the toilet, only to find herself covered in urine.