Akira Nikaido is an easygoing student whose life is about to change after an encounter with a stranger who knows his name. The man, Shirogane, does not possess a shadow and explains that this is because he is a shadow himself. Shirogane then disappears, making Akira think he might have been a ghost. Later that night, Akira's friend Kengo drags him out to 'enjoy' the night at an arcade. There, they save a young child named Haruka and his butler from bullies. Afterwards Aya, the school prefect, finds them. In exchange for not beating them up, she asks for a favor: accompany her to their school so she can pick up something she forgot...