The diligent and well-behaved girl A-chan is assigned to "service duty" after an incident where she's nearly assaulted by her teacher. The job turns out to be simpler than expected—relieving the sexual tension of male students and teachers. Initially restrained to a desk, she's shocked as her big tits spill out, but soon her entire body is massaged with glossy oil, and she easily squirts from just fingering. Since it's her first time on service duty, she asks to be loosened up more—enter the electric massager. The intense vibrations make her juices gush nonstop. Then a vibrator is inserted, turning her pussy into a full-fledged cumdump. As she takes pleasure in the penetration, she's creampie'd, whispering, "It's amazing... so hot...◆" Everyone joins in, shaking her huge breasts as both her mouth and pussy are violated. If that's not enough, her pussy is pried open with a speculum and filled with thick loads from everyone. Dazed with so much cum inside her, she murmurs, "More◆... more...◆" Her mind and body now completely broken into a sex slave. She'll be kept right here as classroom property forever.