Shino Aoi, a small-breasted girl nicknamed "Megumi," lives in constant fear under a disturbing humiliation-based threat. While secretly reading a porn magazine she found by chance, she becomes unintentionally aroused and starts masturbating in hiding—only to be caught by a strange man. He claims he'll keep her secret if she becomes his sex slave, and as Megumi grows increasingly stimulated by the situation, she's dragged into an unexpected turn of events. With sudden changes disrupting her daily life, both her mind and body are shaken to the core.