While Yui husband was away on business, Yui had sex with her only son. Even though she knew it was wrong, her body couldn't stand the loneliness. Their rotten relationship continued secretly even after her husband returned from his job. Yui was worried that her husband would find out. However, her son was enjoying the thrill of the situation. Before she knew it, Yui's son would attack her as soon as her husband left the house.