Mahiro Yui is a plain, sleazy office lady you might spot at the station. But her true nature is that of a perverse exhibitionist who finds pleasure in letting men inhale her rain-soaked, see-through underwear and the "scent of a woman" that wafts from it. Taking advantage of the crowded train, she rubs her strong, childbirth-ready hips against him, seducing him with the intense scent of her steamy private parts. Reaching his limit, the man takes her out and, without even knowing her name, ravages him with 10 creampies. In a closed room where the smell of rain and semen mingle, her plain mask is torn off by pleasure, and the gap between her appearance and her animal-like moans drives him crazy.