A story depicting the underground dealings of a lingerie shop. The underwear sold in-store is often preferred with stains, leading girls to undergo lewd ordeals set up by the staff. A shy, innocent girl is told her panties cannot be purchased unless soiled, forcing her into masturbation. Meanwhile, a half-Japanese girl, desperate for immediate cash, ends up taking a man's penis into her mouth and swallowing his sperm, pushed into an extreme situation. This work fully captures how an ordinary act like underwear trading transforms into a deeply sexual narrative.