Late one night, Kana—an old friend and his best friend’s girlfriend—appears at his tiny apartment after a fight. They drink cheap liquor, eat instant noodles, and reminisce about their student days as adults. Tipsy, she leans against him, and her slender shoulders and unguarded cleavage awaken forbidden desire. He tries to cool off in the bath, only to return and find her even more irresistible without makeup, her hair carrying the familiar scent of shampoo. Lying back-to-back in bed, she asks if he cannot sleep, and in the haze he reaches toward her, beginning the betrayal they will keep secret forever.