When Demon Queen Echidna begins her invasion of the human realm, the people turn to the hero Leo Demonheart to protect them. Blessed with insurmountable power, Leo easily repels Echidna's army, thereby saving the world. But instead of gratitude or admiration, Leo is met with disdain and scorn from his fellow humans, who fear his overwhelming strength and believe that it may eventually cause humanity's demise. Banished from the kingdom he once called home, Leo wanders aimlessly throughout the land until, one day, he hears rumors of Echidna's efforts to rebuild her army. Hoping that demonkind might accept him as an ally, he returns to the demon queen's castle and offers Echidna his help. Naturally, Echidna immediately rejects him. Still, not all hope is lost, as Leo manages to convince Echidna's four generals to let him secretly work under their supervision. Donning the identity of a masked dark knight named Onyx, Leo solves the demon army's problems one by one—gradually improving the quality of life around the castle. Above all else, however, Leo wants to accomplish one goal: to learn why Echidna started the war in the first place.

Every 12 years, mercenaries who possess the highest caliber of brute strength, cunning wit, and deadly precision gather to participate in the Zodiac Tournament. Each warrior bears the name and attributes of one of the 12 animals of the Chinese zodiac. With their pride and lives on the line, they engage in vicious combat until only the victor remains. The 12th Zodiac Tournament begins in a desolate city, devoid of any evidence of the half million people who recently lived there. To raise the stakes, each warrior ingests a poisonous gem, thus setting a time limit on the tournament—and on their life. With one wish for the victor up for grabs, the Zodiac Warriors start their cutthroat battle for survival.

Seven Japanese high school students enjoy international renown for their remarkable talents. One day, these friends survive a plane crash only to find themselves in the medieval fantasy world of Freyjagard, where two human races live side by side in a feudal society: the byuma, who have animal features and formidable strength, and the hyuma, who have a small chance of magical aptitude. After being rescued by the byuma Winona and her adopted elven daughter Lyrule, the group pledges to use their advanced skills and knowledge to pay back the people of Elm Village for their hospitality and find a way to return back home. Tsukasa Mikogami, the prime minister of Japan, acts as the leader of these young geniuses and organizes their efforts to intervene in Freyjagard and gather the information and resources necessary for achieving their goals. Believing that there is a connection between their current situation and an ancient legend about seven heroes from another world who defeated an evil dragon, Tsukasa directs the others to learn about the culture around them and search for any clues leading them back to Earth. But he also gives another instruction: to take it nice and easy, lest they ruin this world by giving it their all.

Following an all-out battle with the Paranormal Liberation Front, it is difficult for the people of Japan to continue placing faith in their heroes. To combat the combined power of Tomura Shigaraki and All For One, All Might calls for his ally from the West—the strongest woman on the planet, Star and Stripe. However, All For One decides to intercept Star and her fleet to get his hands on her overpowered quirk before she can enter Japanese airspace. Although Endeavor, Hawks, and Best Jeanist are headed to the rendezvous point, Star makes a gamble in the present to save her comrades.