Satsuki, a devoted mother with an only son about to advance to school in spring, has raised him with overprotective care. However, her world shatters when she receives news that her son has been caught committing a voyeurism offense. Just as his school admission through recommendation was secured, this scandal erupts. Teachers approach Satsuki, pleading for her cooperation "for the sake of the child," and present her with a settlement condition: she must submit to the school's male teachers for one entire day. Willing to do anything for her beloved son, Satsuki agrees. Yet as the ordeal unfolds, she begins confronting her own latent masochism, spiraling into a new and intense inner conflict.