Puriketsu Kyonyuu ni Sodatta Shinseki no Musume-tachi ga Kuso Shikokatta no de Aherasete Itsudemo Yareru Haramase Onaho ni Shita Ken

Turn these college girls into mindless, moaning sex slaves! Wreck those young eggs and turn them into cock-craving, breeding cum dumpsters in a harem! Our lame-ass protagonist goes home and gets disrespected by his three nieces for being a loser. But when he clashes with the gyaru Kanon fresh out the bath — calling him gross — he snaps and fights back with his dick! He plows through her young pussy, thinking his life’s over... but Kanon becomes obsessed with his cock, turning into his loyal pet! "Fuck it — I’ll show ’em! Young chicks can’t resist this dick!" With that, he punishes the other nieces, Mayu and Sena, turning them into cock-worshipping sluts! His boring life flips — now he fucks raw, does whatever depraved shit he wants, and lives the dream: breeding these moaning, dumbed-out fucktoys nonstop! [Translated from DLsite]