Kikkake wa Sasainakoto

Mayu, a high school girl, oversleeps and rushes to school in her swimsuit to make it in time for the first swimming class. In her haste, she forgets to wear underwear, spending the entire day without a bra or panties. This accidental exposure awakens a secret pleasure in her, leading her to start masturbating in hidden spots around campus.

One day, while indulging in a classroom she believes is empty, three male students unexpectedly enter. Mayu's secret is at risk of being discovered, and the situation quickly spirals into an encounter she never anticipated.