Yuki Sanada is a high school boy who cannot communicate with people well and doesn't have a single friend.
He lives on Enoshima island with his French grandmother. One day, he meets a boy named Haru. Haru calls himself an alien who visited the Earth for fishing.
Another high school boy, Natsuki, and a mysterious Indian, Akira, join the two and the island becomes the center of the event which determines the fate of the world.