After a 7-year absence, Yuuichi Aizawa returns to his aunt Akiko's home in a little northern town. However, he isn't exactly thrilled to be back as all of his memories of the place and its inhabitants have vanished. Even his once playful cousin Nayuki feels like a stranger to him. As he unpacks his belongings, he discovers a red headband that nobody recognizes. This finding prompts him to explore the snowy town, triggering memories of his past - including broken promises and concealed secrets. Yuuichi becomes aware that something supernatural is at play, as he slowly uncovers the connection between his new female acquaintances and his forgotten past.