Threatened and assaulted by students… A female teacher, Hashimoto Arina, becomes a toy for the children, experiencing pleasurable and decadent orgasms. (FSDSS-421)

Arina is dating a teacher colleague at the same school, but recently her feelings have faded, causing her distress. She's also troubled by the problem students in her class. One day, she's discovered using a confiscated vibrator for masturbation, and is subsequently threatened by the students. Unable to resist, Arina is forced to be trained as a sex slave…