This work is a one-shot that was printed in Gangan JOKER the year before the serialization of Happy Sugar Life. It had a great reaction, and so the story became Happy Sugar Life, making this work a prototype. The relationship between Shio and Satou, and the other characters surrounding them, are slightly different. The setting in this story has a slightly different vibe from the serialized work, so I hope you see this as another story to enjoy from a parallel world. (Source: Yen Press)

A boy exploring a world that was destroyed over a hundred years ago one day encounters a shy girl with four black wings. Who is she?