In the near future, bioroids called Iris were created using genes from animals to be the perfect partner for humans. They now live together with humans in harmony. Ryouta is a meddlesome student at Kurama Gakuen who comes upon a stray Iris named Sakura. He decides to take her under his wing and to become her master, but then Sakura’s older sister Ui shows up, along with a suspicious guy Ogami Shingo. Even his schoolmates Ayano and Momoka get involved. It seems that she holds many secrets…