Mizuki and her husband's childhood friend, Murakami, asked them to sign the witness column of the divorce papers. The two of them hesitantly comply, but Murakami, who was away from his wife and had too much sexual desire, became lustful for his friend's wife. Murakami takes advantage of Mizuki's kindness and complains about the pain of being single. Mizuki, who was invited to sympathize, eventually ...