A little girl in Japan receives a doll from her father for her birthday. When the girl is older, the doll is placed on the waves of the sea in a small boat. Apparently a tradition to mark the transition to a new phase of life into adulthood. The girl's brother is present at this farewell to the doll, and suddenly he rushes into the waves to place his lion in the boat as another companion for the doll. He manages to do that, but then disappears forever into the dark sea.
Some time later, another girl travels after her missing doll, and an exciting, adventurous journey begins with an unusual, surprising end.
