Eishi Karasuma is a loner living a monotonous life, with Mikisada Kamoda as his sole friend. One day, while skipping class, the two of them go out together and encounter Tsubame, a highly energetic girl, and Rei Sagisawa, a handsome boy who attends the same middle school. On their way back to school, a sudden incident occurs. A mysterious boy with wings arrives to help.