Beings who possess animal-like powers walk among humans in this alternate universe. These mysterious mutants, the +Anima, are shunned by society. Four outcasts in particular - Cooro, a boy with crow-like powers; Husky, a fish-boy; Senri, a bear +Anima; and a girl named Nana, who wields the power of the bat - search for others like themselves while trying to gain acceptance in a world cruel to anyone or anything that is different.

Cooro and the others discover the first Yellow Valley Race, a race exclusively for +Anima. Cooro and Senri decide to enter, and while waiting for the race to start, they run into Lyra, a girl whom Cooro knew when he was younger. But when Cooro knew her, she wasn't a +Anima... How can she be one now - and is that the only secret she holds?

Cooro and his +ANIMA friends find themselves in the beehive forest. Cooro ends up doing a favor for people in a nearby town. His +ANIMA powers must help him stop a stinging foe! The +ANIMA band's troubles never cease as their adventure continues.

Husky, Senri, Nana and Cooro happen upon an apple orchard owned by a lonely woman named Emma, who invites them all to stay with her. But while the others feel her offer to be a little unsettling and would rather leave, Cooro couldn't be happier to have finally found a mother. Cooro's long journey of acceptance may finally be over... but are the others prepared to leave him behind?

The party, led by Igneous, come across a bear in the mountains just as something goes wrong with Senri and he collapses. The Kim-un-kur let Igneous and his troops into their camp because they are concerned about Senri... but their chief, Mukar, tells them that he has no intention of changing their relations with Astaria.

As AI debugger Albireo journeys further into The World, he discovers that there is one AI who cannot be killed with his legendary spear of Wotan. Crossing the rifts of time, his divine weapon - and Albireo's lonely heart - reach one special girl, called Kamui. This story of heroics continues the .Hack series, as AI Buster Volume 2 reveals the hidden truth behind the Twilight Bracelet and the mysterious Record of the Created World.

As Nanase engages in the popular online game, The World, she falls in love with Silabus, her guildmaster. However, everyone has their eyes glued to the new Arena Champion Alkaid, and Silabus is no exception! As Alkaid continues to cast a big shadow, Nanase is forced to realize that her quiet, helpless attitude is the source of all her problems. But when Silabus is in serious trouble and her loyalty to the guild is challenged, what action will Nanase take? Can her weakness be her strength?!

In order for Akira to save her younger brother, who suddenly lost consciousness in the middle of playing in The World, she enters The World as the swords-woman Black Rose. There Black Rose squares off against the double-knife fighter, Kite.

Akira once again enters the online game The World in order to save her younger brother, who has lapsed into a coma. With the virus infection now spreading to protected areas, she joins forces with Kite to unravel the mystery of the Epitaph of the Twilight and the Cursed Wave. But the two of them couldn't battle it out alone! Should they make a deal with Balmung? And should Akira reveal the secret of her brother's condition?

The World is further corrupted as the game expands into our reality. With Aura and her bracelet, BlackRose (aka Akira) discovers the answers to some important questions. They help shed light on Corbenik, the virus at the source of all the trouble. Will Akira, along with the aid of her comrades in The World, be able to save her comatose brother in time?

"The World" is a massively multiplayer online game played by more than twelve million people across the globe. Within this virtual world Haseo, a PKK (Player Killer Killer), continues an endless fight. However, on finally meeting with his sole lead, a PK called "Tri-Edge," Haseo is dropped back to Level 1 by a mysterious power! Can Haseo save Shino now that he has lost all of his abilities?

In the seven years since the events of the original series, Altimit OS been replaced by Altimit Mine OS and The World has become The World R:2, a dangerous game overrun by player killers and where lawlessness abounds. Follow Haseo as he chases Tri-Edge and gets involved with Project G.U. and mysterious SIDA who plague The World R:2!