The man was thinking about marrying his live-in girlfriend. She had a younger sister, Akari, who often came to play at their house. One day, Akari was caught in a sudden downpour and was drenched when she came to take shelter. However, her sister was stuck at work, leaving just the man and Akari alone. Although he usually thought of her as a cute younger sister, the sight of her wet, transparent body made him feel a woman he had never felt before, and he lost his reason and took her lips. And they sought each other out many times until morning.
