All living humans are giant fish in the sea; when they are born, they start from this side of the sea. Their lives are like crossing the sea, sometimes meeting, sometimes parting... When they die, they reach the shore and go to their own worlds. Four and a half billion years ago, there was only a vast ocean and a group of ancient giant fish on this planet. In a space parallel to the human world, there lives a well-behaved and orderly tribe. They work for God, manage the laws of the operation of all things in the world, and also manage the souls of humans. Their sky is connected to the sea of the human world. They are neither gods nor humans, they are "others". On her sixteenth birthday, a girl named Chun (voiced by Ji Guanlin) who lives in the "God's Tower" turned into a dolphin to visit the human world and was trapped by a net in the sea. A human boy fell into the deep sea and died because he saved her. In order to repay her gratitude and to revive the human boy, she needs to go through all kinds of difficulties and obstacles in her own world to help the boy's soul after death - a small fish as big as a thumb, grow into a fish larger than a whale and return to the sea.