Waking up cold and alone in the woods, a nameless man is surrounded by unfamiliar scenes. Without any memories, he is utterly lost until he stumbles upon Kuon—a young girl with animal ears and a tail. She saves him, leading him back to her town while protecting them both from "boro-gigiri"—giant centipede-like creatures—and a mysterious red slime. After they arrive, she names him Haku after a prominent historical fig...