.hack//Roots is a 26-episode anime series that serves as a prequel to the .hack//G.U. video games. It was animated by studio Bee Train and aired in Japan from April 5, 2006 to September 27, 2006. It was also the first .hack TV series to be broadcast in HDTV (1080i).

The story revolves around an MMORPG game called The World R:2, which is a sequel to the original version of The World. The main character is Haseo, a newcomer who is instantly killed by a player killer (PK) and then revived by a mysterious man named Ovan. Haseo joins Ovan’s guild, the Twilight Brigade, which is searching for a legendary item called the Key of the Twilight. Along the way, he meets various friends and foes, and learns more about the secrets of The World R:2.

.hack//Roots was licensed by Bandai Entertainment in North America, with dubbing handled by The Ocean Group. However, due to spoilers for the games that were not yet released, Cartoon Network only aired 21 episodes and skipped the last five. The series was later acquired by Funimation, which released it on DVD and Blu-ray.

One of the main attractions of .hack//Roots is its large and diverse cast of characters, each with their own personality, background, and motivation. Some of them are based on the characters from the previous .hack series, while others are original creations for this anime. The voice actors for the characters are also well-known in the anime industry, both in Japan and abroad.

The protagonist of the series is Haseo, voiced by Takahiro Sakurai in Japanese and Andrew Francis in English. He is a cold and ruthless player who seeks revenge against Tri-Edge, a mysterious PK who put his friend Shino into a coma. He is also the wielder of the Xth Form, a powerful weapon that can change its shape according to his will. Haseo is often accompanied by his friends Tabby and Sakisaka, voiced by Megumi Toyoguchi and Ryotaro Okiayu in Japanese and Marke Hendrikse and Alistair Abell in English, respectively. Tabby is a cheerful and energetic catgirl who likes to help others, while Sakisaka is a calm and sarcastic swordsman who acts as Haseo’s mentor.

The leader of the Twilight Brigade is Ovan, voiced by Hiroki Tochi in Japanese and Michael Kopsa in English. He is a mysterious and charismatic man who wears a large metal arm that conceals a secret. He is the one who invites Haseo to join his guild and guides him to find the Key of the Twilight. He also has a close relationship with Shino, voiced by Kaori Nazuka in Japanese and Kelly Sheridan in English. She is a kind and gentle healer who cares deeply for Haseo and Ovan. She is also the victim of Tri-Edge’s attack that triggers the main plot of the series.

The main conflict of the series is the search for the Key of the Twilight, a mysterious item that is said to have the power to change anything in The World R:2. Ovan claims that he knows where to find it, and leads the Twilight Brigade on a quest to collect six Virus Cores, special items that can access hidden areas called Lost Grounds. However, their mission is opposed by TaN, a guild that is secretly controlled by Yata and Pi, two system administrators who are investigating Ovan’s true identity and motives.

As the Twilight Brigade gathers all the Virus Cores, they head to one of the Lost Grounds, where Ovan reveals that he has been using them as bait to lure out Tri-Edge, a mysterious PK who has been killing players and putting them into comas in real life. Ovan challenges Tri-Edge to a duel, but is defeated and disappears from the game. The Twilight Brigade disbands, and Haseo vows to find Ovan and Tri-Edge.

Haseo becomes obsessed with hunting down PKs and increasing his level, hoping to gain enough strength to face Tri-Edge. He also encounters several characters who will play important roles in his future, such as Kuhn, a flirtatious Steam Gunner who introduces him to the concept of Avatar; Piros the 3rd, a comic relief character who claims to be a legendary hero; and Atoli, a kind-hearted Harvest Cleric who tries to befriend Haseo despite his cold attitude.

The series ends with Haseo finally confronting Tri-Edge at the same Lost Ground where Shino was attacked. He discovers that Tri-Edge is actually a corrupted version of Kite, the hero of the previous .hack series. Haseo tries to fight him with his Xth Form, but is overwhelmed by Tri-Edge’s power and data drained. He wakes up in a new form, resembling a skeleton with red eyes. He realizes that he has become an Epitaph User, a rare type of player who can use an Avatar, a powerful manifestation of their inner self. He also receives an email from Ovan, telling him to seek out the Forest of Pain.