His wife's mother is a widow, so they end up living under the same roof. When his wife is away, the two of them are left alone... Hitomi becomes aroused by her son-in-law's morning erection. Yurie's sexually promiscuous side is witnessed by her son-in-law. Shiho is seduced by her son-in-law, who becomes aroused by the sexy underwear she finds on the laundry. Ayako, a dirty woman, is looked after by her son-in-law. This book contains four forbidden stories of beautiful stepmothers and their sons-in-law.