A young man becomes host to a legendary infernal sword and, with the fate of humanity now in his arm, wields its demonic power against his enemies.

The anime follows Makoto, a young boy who gains superpowers due to an evil gene manipulation experiment. Makoto and other youths join the Avengers as apprentices named "Future Avengers." The anime will show Makoto and others as they train, fight villains and grow, under Avengers members Iron Man, Captain America, Hulk, Thor, and Wasp.

Riley, now 12, is hanging out at home with her parents in San Francisco when potential trouble comes knocking: a boy shows up at the door.

Known as a Rogue Hero in the fantasy world Arezard, Akatsuki decided to take upon the request of the defeated Demon King to take his daughter with him. After bringing her back to the world he came from, Akatsuki brought her to join Babel, an academy-like organization that specializes in training those who came from the other world.