Yuzuru is staying with his brother in order to attend a cram school in Tokyo. Stressed about his exams, he starts to become aware of his brother's kind and beautiful wife. A few days later, at dusk, Tsukasa returns home from shopping soaked after a sudden downpour. Wet hair, a see-through bra, and the adult sex appeal of her make Yuzuru lose his sense of reason and he unleashes his sexual desires. "It's no use..." He thought he would be kicked out of his brother's house, but...