After marriage, when his wife began seeking more frequent intimacy, Takeru found himself uninterested. The reason? He was captivated by the alluring presence of his wife's mother, Ruriko, who lived with them. Despite having his wife by his side, he couldn't help but be drawn to Ruriko's beauty and sensual charm, losing all self-control. Fully aware of how wrong it was, he still felt an overwhelming urge to reach out and touch her—until one day, he couldn't resist and ended up peeping at her while she was changing clothes.