Akito Haga, a junior at Takashiro High School, prays each day at a neighborhood shrine for direction in his life. One day, however, he changes his prayers and pleads to "just give me anything". Suddenly, a girl with angel wings falls from the sky and collides with him. The girl, later named Marino, suffers from amnesia and is looked after by the shrine's priest. Confused by this, Akito leaves the shrine when he literally collides into yet another mysterious girl, Musia, on the stairway. She claims to be an emulate and wants to enter into a contract with him.