Sakuraba Iris falls from the sky and saves Karasuma Crow from a black monster at his high school. Iris explains that these monsters are called Ravens who hunt those who have large amounts of “flaps”, an aura-like power. Iris herself is a “Luke” who solidifies her flaps to create a weapon to fight and destroy Ravens. Crow accidentally breaks the trinket that lets Iris transform, but finds out that his aura has the same ability as the trinket and Iris can defeat Ravens with the help of Crow. Now they must next to each other to defend themselves from the Ravens, so Iris moves into Crow's house!