Shinji lives with his parents-in-law after marrying into the family. He is living a peaceful life with his wife and mother-in-law when his sister-in-law Tsumugi, who had a fight with her husband, comes to stay with them...? The house is a mess because of his lazy sister-in-law. On top of that, he is frustrated because he is refused sex with his wife because "my sister-in-law will find out." One day, he witnesses Tsumugi masturbating and becomes aroused by his lazy sister-in-law, who should have been irritating him. Unable to bear it any longer, Shinji asks Tsumugi to give him a handjob, but Tsumugi's response is unexpected...