The perverted old man living next door is excited every day by eavesdropping on the sounds of urine from Nanami-chan, who lives next to him. One day, he witnesses her in distress because she has lost her key. When he approaches her, he notices her fidgeting and pressing her crotch, realizing she is at the limit of her bladder's capacity. His long-held desires explode. He takes her to the trash room, stimulates her bladder, and forces her to wet herself! His desire for urine escalates further, and he administers a diuretic aphrodisiac, imprisoning her and engaging in forced sex! His rationality flies out the window as he experiences incontinence and multiple orgasms! Through raw, disciplined mating, he drowns her mind until it melts, and she becomes unable to return to being an ordinary girl...