An unusual fantasy love story of Wan, a girl who's born with the supernatural ability to stay underwater. While visiting Butterfly Island, Wan discovers her special ability to dive and stay under deep sea. She also meets Tan, a photographer who always helps her when she has problems, and with whom she eventually falls in love. Wan soon realizes that her new-found powers come with a price; she's not a normal girl. Her body will be transferred into a kind of creature when she gets into the water. Once again, it's Tan who must help Wan figure out what's going on with her body without knowing that a mysterious secret awaits him under the sea.
Strange things start happening when separate twists of fate bring each of three friends, Big, Dan and Beam, into contact with three strangers – an old woman who tells prophecies, a little girl who sells garlands on the street and a young woman named Aom.