Akira, Jin, and Lena are close friends. Together they live and study on a planet called Rem. Once when they were together in the library, they found a mysterious book titled Akuma Compendium. Curiosity with ancient contents written in it. They found ways to decode but only get a single sentence. Unexpectedly, it was a spell that revealed the vision of the future world. A door of time opened, and what they saw was the destruction of the world, started by the evil Imperius. He lives in the land of Valhalla, inhabited by demons. The development rate there is so fast, but the area was extremely tight, so he intends to replace it with Rem. Jin, Akira, and Lena decide to keep the secret as well as privately go to Valhalla to stop the threat. But will they succeed when Imperius’ army is so crowded and aggressive?
