The incantation pulls you into a world where kids are casually given the power to command demons, and the show never questions whether that's a good idea. Jin and Akira don't save the world because they're chosen, they save it because they accidentally opened the door and now they're the only ones who can close it. That gap between "we found a magic book" and "we're responsible for everything" is where this show lives, and it never lets either character forget the weight of their own carelessness.

Jin, Akira and Lena are three longtime friends drawn to anything mysterious. While in the library with Ami, a puzzling new transfer student, they come across a book called the Akuma Compendium, and reading its incantation aloud makes devils appear. Ami tells Jin and Akira that they are Devil Children who will decide the fate of the world, and she gives them devices called Devil Risers. The group crosses into Valhalla, a land where humans and devils once lived side by side, and there they oppose Imperius, a ruler bent on conquering the whole world. Jin gains the Sol Lion Rand as his partner, while Akira is joined by the Hylon Gale. To restore peace to Valhalla and find their way home, they must recover the scattered fragments of the Key of Time, facing a stream of devils determined to stop them. Expect an action fantasy adventure built around partner creatures and battles.