It’s been 7 years since Yuuichi Aizawa visited his aunt Akiko, but now that his parents have gone to Africa to pursue their careers, he is finally back in the little northern town. Yuuichi is not really overjoyed with the prospect of living here though, because all of his memories of this place and the people living in it have mysteriously vanished. His cute cousin Nayuki seems like a stranger as well, even though he used to play with her all the time when they were younger.

On the day of moving into his new home, Yuuichi starts unpacking the boxes and stumbles upon a red headband that no one seems to recognize. This is one of the first clues that will make Yuuichi take a stroll through the snow-covered town and make him start recalling fragments of his past, broken promises and buried secrets. Yuuichi soon realizes that there is something supernatural going on, and all of his new female acquaintances seem to have links to his forgotten past.