The island is located on Urashima, a remote island. The island's three largest families, which once enjoyed a carefree way of life, have been skeptical of one another for the past five years as a result of a string of disasters. Since then, the island's population has severed all ties to the mainland, which has caused a gradually declining population.
Three daughters, each from one of the three great families, have the key to rescuing the island. These, however, are constrained by long-standing customs. .. A lonesome guy suddenly washes up on the coast, claiming to be from the future, and he immediately starts to fight alone against destiny to save the island.