Natsuki isn´t like the other girls. She has a wand and a transformation mirror. She might be a witch, or an alien from another planet. Together with her cousin Yuu, Natsuki spends her summers in the wild mountains of Nagano, dreaming of other worlds. When a terrible sequence of events threatens to part the two children forever, they make a promise: survive, no matter what. Now Natsuki is grown. She lives a quiet life with her asexual husband, surviving as best she can by pretending to be normal. But the demands of Natsuki´s family are increasing, her friends wonder why she´s still not pregnant, and dark shadows from Natsuki´s childhood are pursuing her. Fleeing the suburbs for the mountains of her childhood, Natsuki prepares herself with a reunion with Yuu. Will he still remember their promise? And will he help her keep it?