Oppai Heart Kanojo Wa Kedamono Hatsujouki!

Miya is the older stepsister of Ruuya. The dude lives an average life and most of the time he is with his friend. His life changes when he randomly chugs a drink which arouses his sexuality! So, now he is insatiable and has lots of nympho fun until he ends up finding the vaccine for the drink. Amazing hentai!