The characters from previous .hack//G.U. Games and .hack//Roots receive an email from Ovan. He is requesting them to go to Hidden Forbidden Festival where is set up a mysterious summer festival. There they find an AIDA Chim Chim who wishes to peacefully co-exist with the other players of The World. It then transforms into the word "Returner", so they assume it to mean that Ovan will return to The World.

For high schooler Kei—and for at least forty-six others—immortality comes as the nastiest surprise ever. Sadly for Kei, such a feat doesn't make him a superhero. In the eyes of both the general public and governments, he's a rare specimen who needs to be hunted down and handed over to scientists to be experimented on for life—a demi-human who must die a thousand deaths for the benefit of humanity.

Two years after the battle against Eosmon, Davis Motomiya, Ken Ichijouji, Yolei Inoue, Cody Hida, T.K. Takaishi, and Kari Kamiya meet a boy named Rui Owada, who is found with a depowered Digivice and claims to be the first Digidestined ever. In addition, a Digimon named Ukkomon appears in the real world, who wants every person in the world to have their own Digimon partner.

Amatsuki Meguru is a girl who innocently aspires to be a hero of justice and the cool Kisaragi Sumire who grew up in the strict Kisaragi household... The two girls who are in their 3rd year of middle school end up getting orders from a mysterious hedgehog named Miruku-chan and turn into Twin Angels in order to fight evil! Meguru is always cheerful but sometimes a bit too forceful. Meanwhile, Sumire isn't accustomed with being around others. Despite their differences, as they work together, they start opening up to each other. (Source: Crunchyroll)