.hack//SIGN

.hack//SIGN is a 26 episode anime that revolves around a Wavemaster named Tsukasa who becomes mysteriously trapped in The World, and also about a group of players who wish to find a mysterious item called the Key of the Twilight.

Despite taking place in a fantasy quest type The World, it does not rely on action sequences in the unraveling of the story. Instead, the show is driven by mystery, slowly revealing its secrets to the viewer while paying much attention to the individual characters. Questions like what happened to Tsukasa in the real world, who he really is and why he is unable to log out are driving points of the story.

Near the beginning of the series Morganna orders part of her program, Macha, to lead the character Tsukasa to the bottom of a dungeon and Data Drained him, trapping him within the system. She uses her control over the data of The World to modify his memories, making him believe that he is actually male in the real world, and erasing his happy memories, leaving only the memories of his abusive father.

Thus Tsukasa meets Morganna, depicted as a voice without physical appearance, and Aura, who appears as a young girl clad entirely in white, floating asleep above a bed. Morganna uses him to help her stall the growth of Aura. By surrounding the fledgling Ultimate AI with only negative emotions, she is able to postpone Aura's awakening indefinitely, avoiding the paradox she fears, while still fulfilling Aura's need for emotional data.

In order to keep Tsukasa inside of the system, Morganna provides him with a powerful monster, a Twilight Guardian, to serve as his protector. She also gave him the ability to teleport between fields and servers without having to use a Chaos Gate; with this ability Tsukasa was able to access the isolated area where Aura was kept, along with other areas inside The World that could not be reached by normal players.

Morganna's plan went well at first. Tsukasa seemed happy enough even though he was trapped within The World, for he experienced power and safety that he had not had in the real world.

As the story progresses many characters are introduced, some who want to help, some who have their own ulterior motives.

Left to Right: Crim, Sora, Silver Knight, Subaru, BT, Bear, Mimiru and Tsukasa

More questions arise as to "what is happening in the game itself, who are these various characters, what are their true goals and what will happen to Tsukasa". All the while he is seen struggling with his increasingly dire situation as well as his own social and emotional short comings. Tsukasa isolates himself, but eventually he begins to get closer to other players, and builds strong relationships with some of them. The most important is that which is born between him and Subaru, a kind and thoughtful female Heavy Axe.

In the meantime, the anime follows the quest for the Key of the Twilight (黄昏の鍵 Tasogare no Kagi), a legendary item rumored to have the ability to bypass the system in The World. Some characters want the Key to gain the power this supposedly confers. Others believe the item will provide Tsukasa with a way to log out. Despite the reasons for seeking it, everyone agrees that it is related to Tsukasa in some way, as he is also a factor bypassing the system in the game. His body being in a coma in the real world adds a sense of urgency to the quest.,

Near the end of the series Tsukasa's real-life identity takes a more central place in the storyline, particularly in relation to his growing bond with Subaru. The series shows his fear and insecurity as he confesses to her that he is probably a girl in the real world. It is also at this point when Tsukasa is told Morganna's plan by a highly skilled hacker called Helba.

Morganna conceived the plan to link Aura to a character who could corrupt her with negative emotional data, placing her in a state where she would never awaken. The chosen character was Tsukasa, as his mind was filled with distressful memories of his real life. Helba also suggests that when Aura is able to awaken, "the Key of the Twilight will take form".

The determined players slowly began to unravel the mystery behind Tsukasa, and awoke in him the desire to return to reality. Morganna tried various methods to keep Tsukasa within the system, but in the end all of them failed. Even a fragment of Morganna's own self, Macha, turned against her, forcing Morganna to Data Drain her in order to get her out of the way.

The story reaches its climax when Tsukasa confronts Morganna. Then the viewer sees him declaring that he is no longer afraid of her or of reality, and will log out because there is someone he wants to see.

This statement triggers Aura's awakening, allowing Tsukasa to log out. The last scenes feature an emotional encounter between Tsukasa's real-life self, finally shown to be a girl, and the real-life player behind Subaru.

Seeing that her plan has failed, Morganna was filled with rage. She ordered another of the phases, Skeith, to hunt down and capture her.

This marked the end of .hack//SIGN, and the start of .hack//Infection.

Clockwise from top right: Sora, Crim, BT, Subaru, Tsukasa, Mimiru, Helba, and Bear.