.hack//Portal

.hack//Roots is the prequel to the .hack//G.U. games trilogy, as .hack//SIGN was to first 4 part game series. Directed by Koichi Mashimo, and animated by studio Bee Train, this 26 episode series is the first .hack tv series to be broadcasted on HDTV. The opening theme song is "Silly-Go-Round" composed by Yuki Kajiura and performed by FictionJunction YUUKA, the ending theme is "Boukoku Kakusei Catharsis", by Ali Project. There are two full OST's, and two singles for .hack//Roots.

In 2015, a devastating fire at CC Corp. main building destroyed most of 'The World's' game data, causing the game to be taken offline. Salvaging any remainder data from 'The World', CC Corp. created 'The World R:2', and released it in 2016. A introduction to Guild PVP (player vs player) was created, and slowly players started playing again.

.hack//Roots begins 8 months before .hack//G.U. and ends during the events of the first .hack//G.U. game, Rebirth. The plot revolves around an Adept Rogue named Haseo, a newbie player to 'The World R:2'. On Haseo's first login to the game, he is PKed by some other players, but is saved by a mysterious Steam Gunner named Ovan. He tells Haseo that he is special and needs to become stronger, then invites Haseo to his guild the Twilight Brigade.

Haseo is pursuing the elusive PKer "Tri-Edge", known for PKing his close friend Shino causing her to go into a coma. Anyone attacked by Tri-Edge are known as "Lost Ones", due to them never logging back in, and going into comas. Stopping at nothing to unlock the mysteries of 'The World R:2', Haseo embarks on journeys that he may or may not return from.