Itsuki Watase’s old man remarries, dragging a new stepmom, Otoha, and two stepsisters, Nagisa and Fuka, into his life—no blood ties, just a stitched-together family of strangers. At first, the Watase crew gets along like some picture-perfect sitcom—tight-knit, almost too cozy. But Otoha’s a knockout, Nagisa and Fuka are just as tempting, and Itsuki’s stuck in a house dripping with sex appeal. He tries to play the good son, the good brother, but every day their curves and closeness chip away at him, his lust clawing its way out.

 

Then he catches his dad cheating on Otoha. The betrayal hits like a brick—here he’s been choking down his own sick urges, and his father’s out there screwing around? He’s done playing nice. If his dad’s tossing this family aside, Itsuki’s claiming it. They’re his now.

 

One night, he finds Otoha dozing on the couch, her negligee barely clinging to her unprotected body. He can’t hold back anymore—his hands bury into her plump breasts, lips slick with want, molesting her right there. He’s lost in it, until Nagisa’s voice cuts through the dark: “What… what are you doing? You were kissing your mom just now…?” She’s trembling, wide-eyed in the living room, catching him mid-act. That moment flips everything—the Watase family’s fake harmony explodes into a twisted paradise, a feeding ground for Itsuki’s unleashed desires.