 They are known as "Knights" because when people are taken to Endia, they obtain powers like any other.When Hyoma asks how to get back to his world, Rin explains that there is no way to return.Hyoma doesn't accept this fact and decides to find a way, but there, they then encounter the "Luin", an Organization that is determined to find "Keys" (mechanisms used to open gates and to summon "knights") in order to make their "paradise".