When Hiroyuki Takanoi's father remarries, he moves in with his new stepmother, Kyouko, and her two daughters, the innocent Futaba and the assertive Ichika. The sexually frustrated Hiroyuki can't contain his lust, starting with his stepsister Ichika. He ambushes her, tearing off her clothes and fucking her relentlessly until she's a moaning mess. His conquest doesn't stop there. He soon moves on to the shy Futaba, bending her over and filling her tight pussy with his seed. The series culminates in the ultimate taboo as he seduces his busty stepmother, Kyouko, engaging in a passionate, sweat-drenched breeding session that solidifies his sexual dominance over the entire household. Each episode escalates the raw, incestuous debauchery, showing every graphic detail of Hiroyuki plowing his new family and ejaculating deep inside them.