A documentary-style portrayal of underground transactions involving used underwear at a lingerie shop's backroom. Schoolgirls in uniforms come to sell their stained panties. The girls are tormented by lewd pranks from the shop clerk, desperately trying to meet the strict condition that only soiled panties will be purchased. Their anxious, flustered reactions heighten the tension and excitement. Vibrators are inserted into their panties, capturing their realistic moans and arousal. Tempted by higher payments, an extra-large-breasted girl sucks a man's cock in the storage room. A beautiful uniformed girl has an electric massager pressed against her, dripping with abundant love juice. A half-Japanese beauty trades her young pussy for pocket money, penetrated vigorously on camera. The climax of the film features these girls writhing and screaming in ecstasy.