Momo is a young girl who grew up in a big city. However, following the premature loss of her father, she has to move with her mother to the old family house on a remote island. Here, time seems to have stopped: old wooden buildings, holy shrines surrounded by trees, fields painstakingly carved out from steep hills... and no shopping mall. <br><br> Needless to say, Momo is not too overenthusiastic about this new environment. Most of all, her heart is still feeling uneasy about an unfinished letter left by her father. A letter that contained only two words: "Dear Momo..." <br><br> What was dad going to say? <br><br> One day, exploring the attic of her new big house, Momo finds a dusty and worn out book. And from that moment, something really unexpected starts happening around her... <br><br> (Source: Production I.G Official Website)