Momo is a young girl from the big city. Following her father’s sudden death, she has to move with her mother to the old family house on a remote island where time seems to have stopped: old wooden buildings, holy shrines, terraced fields… and no shopping mall. Needless to say, Momo is not too enthusiastic. Worst of all, her heart is still feeling uneasy about an unfinished letter her father left behind: Dear Momo. What was her dad going to say? One day, exploring the attic of her new house, Momo finds an ancient book. And from that moment, strange things start happening.