The second son and his wife came back to their parents' house for the first time in 20 years. The two are welcomed by the eldest son and his wife, the third son and his fiancé, around the hearth. The eldest son's wife, Sachiko, and the second son, Ken, were classmates in high school. The woman who was Ken's idol is now his brother's wife. And the second son's wife, Yoshie, looks like she's licking the eldest son, Umekichi's body. The next day, these three pairs of brothers and sisters will experience a forbidden world that shouldn't exist...! An intimate love drama drawn by erotic mass Katsuya Ichihara!