Okamoto takes home Kana, a good worker but gloomy girl, from a drinking party. She's plain, so he doesn't think she'll have a good body, just like her face, but when he takes her off, he finds out she has a voluptuous body that's full of pheromones. He learns that she's a slutty masochist who does lascivious yoga, and decides to make Kana melt with his dick.