Yukina Kanazaki, known as "snow queen" or "dark queen" in her school, but one day she received a magical letter that can open the door to the other realm. and because of a massive war is going on long ago they sent yukina to the human realm and erased her memories about the other realm to protect her from the other kingdom's plots. so join in her journey to get the fragments of her memories in different realm, and see whats waiting for her there.