A perverted old man gets excited every day when he eavesdrops on the sound of his neighbor Nanami urinating. One day, he sees her in trouble after losing her keys. When he calls out to her, he sees her fidgeting and clutching her crotch, and realizes that she is at the limit of her need to pee, and his long-held desire explodes. He takes her to a garbage room, stimulates her bladder, and makes her wet herself! Her desire to pee escalates even further, so he gives her a diuretic aphrodisiac and rapes her while confining her! She loses her mind and climaxes over and over again as she urinates! She is trained and fucked raw until her brain melts, and she can never go back to being a normal girl...