After the loss of her father, young Momo moves to the old family house on a remote island: wooden buildings, terraced fields... and no shopping mall. Not too fond of the new environment, Momo is also feeling uneasy about an unfinished letter her father left behind with only two words: "Dear Momo". Then, exploring the attic of her new house, she finds an antique book — and from that moment on, strange happenings occur all around her.