Yu, a married woman who grows frustrated with her husband who masturbates in secret without even embracing her. - While he was masturbating himself, his neighbor Misawa saw him through the window he had forgotten to close. - Misawa desperately apologizes and says he didn't mean any harm, but Yu senses his sincerity and consults him about her dissatisfaction with her husband. - The two of them feel a change in their crotches as they talk about sex. - The two were never supposed to meet, but after witnessing this masturbation, they end up having an affair so intense that they end up sweating...