“Urashima” floating in the ocean far away from the mainland There was rich nature that seemed to be paradise, and people caught in complicated past and tradition were breathtaking islands. A resident of an island living while losing sight from the mainland, missing halfway in this place while being forgotten. One young man who self-named “Time Traveler” flows to such an island. The young man who had lost his memory other than “Sotsuna” and “a certain mission” meets three girls, Rinno, Natsumura and Sara, and eventually begins to change the island’s future. The story of young people and girls surrounding Urashima who has exclusive conventions and numerous mysteries is unraveled.