Under the ocean is a mystical race of beings that control the tide and the changing of the seasons. One of these beings, a restless young girl named Chun, wants to experience the human world, not simply observe it. When she turns sixteen, she is allowed to transform into a dolphin to explore the human world. However, the world is a dangerous place. Trapped in a vortex, she is nearly killed but saved at the last minute by a human boy.