An accident occuring in "The World", will be solved in the net framework space, with the OVA "Liminality". Mai and Kasumi collapse in the real world, however, only Mai recovers, leaving Tomonari in a coma. The incident will be investigated through the real world point of view. You will continue to come closer to the truth of the accident within the game while investigating from the real world in the OVA.

In 2015, CC Corporation`s datacenter caught on fire destroying "The World". By splicing in data from what would have been another project, CC Corp. was able to rebuild the game. In 2016, "The World R:2" was released. .hack//Roots covers the time Haseo spent with Shino and Ovan in the guild known as the Twilight Brigade, before the .hack//G.U. PS2 games.

Amidst a popular online role playing game in the near future, characters try to play out the goals they set for entertainment and passing of time. The World as the RPG is called is one with a setting of monsters, player characters and dungeons. Tsukasa is a detached and introverted character that has a number of mysteries about his player character. Many weird happenings seem to suround Tsukasa and his involvement in a rare item called 'The Key Of The Twilight' sparks Tsukasa's meeting with different online characters and the befriending of their real life counterparts; All without ever meeting face to face in reality.

Shugo and his twin sister Rena, two new players in The World, (a future online roleplaying game) are caught up in an unknown agenda. Unstopable monsters have started appearing and players that encounter these monsters fall into comas in the real world. Playing the limited edition characters, Kite and Black Rose, and the wielding the mysterious twilight bracelet, the two siblings must figure out what is going on and stop it before the damage escalates.

In an alternate world, the Cold War has continued to persist for 140 years. As a result, the world was divided into two factions: the West Block, and the East Block. As the Cold War drags on, the tension between the two factions, as well as the amount of nuclear weapons they have, rise. Mylene Hoffman is a female cyborg who is a spy for the West Block. Together with three other agents, Mylene partakes in various missions issued by her superiors.

Barsburg Empire's Military Academy has always been known for training the elite with potential to become superb soldiers who won't bring shame to the name of the empire. The students of the special program freely utilize an ability called "zaiphon" to fight... Everyone's capabilities are different, and in many cases, reflect their nature. However, not everything is what it seems, and nothing will be the same for Teito Klein after passing the last exam...

Satsuki Kakeru lost his sister by suicide and has been living a dull life ever since then. One day, he is transported into a bizarre world "Red Night" along with his friend Minase Yuka. In order to survive and escape from Red Night, he fights against Dark Spirits (Ralva) and Black Nights.

Yoko Nakajima, an unhappy high school student, is one day suddenly faced with a strange man who swears allegiance to her. After a battle with demon-like beasts, he then takes her to another world along with two of her classmates. There, her appearance has changed and she can understand the language even though her classmates cannot. But their status as "Kaikyaku" (people who come from Earth) makes them hunted fugitives, so they wander the land of the 12 countries, simply trying to survive and to figure out the reason why they were brought to this world.

3X3 Eyes is the story of a young man named Yakumo Fuuji, who through a strange series of events becomes the immortal slave of the last of a race of 3 Eyed immortals. The immortal absorbs his soul to save his life, making him immortal in the process.

Yakumo has trained and searched for 4 years, following Pai's mysterious disappearance. However, when he finally finds her, not all is well as her memory seems to be gone. They attempt to return her memory by going to the Holy Land, birthplace of the immortal race of Sanjiyans.