''.hack//Liminality'' is a 4-episode {{OVA}} which deals with what is occurring in the real world during the time period of the first four ''VideoGame/DotHackR1Games'' games. The OVA was originally distributed as a bonus with the games, one DVD per installment. However, subsequent re-releases haven't included the UsefulNotes/{{DVD}}s, and they can be hard to find used. In Japan, the {{OVA}}s were re-released separately as part of ".hack//Integration", a campaign to help consolidate the multimedia franchise. ''Liminality'' is unique among .hack// in that it is set entirely in the real world; there are a few segments where the characters play the game, but we never see the game through their eyes during these scenes.

The plot deals with former [[MegaCorp CC Corp]] Employee Junichiro Tokuoka investigating the mysterious comas that players are falling into while playing The World. He first runs into Mai Minase, who managed to avoid falling into a coma, even though the boy she was playing with did. The two team up, and eventually meet with two of the boy's online friends to enact a plan and help wake the coma victims up.

See Franchise/DotHack for information about the franchise as a whole.

There are [[Characters/DotHack character sheets]].

!!!This anime contains examples of the following tropes:

* BatDeduction: When Tokuoka and Kyoko are sent from place to place finding clues, they stop for a moment. Tokuoka deduces that the game of clue-hunting is meant to [[FetchQuest resemble an RPG]]. This appears to be totally right.
* BigOlEyebrows: Mai has a pair of these.
* {{Bowdlerisation}}: In the Japanese version of "The Case of Mai Minase", Skeith's wand has a cross shape visible at the top; in the American version, the cross shape is changed to the Q shape used in ''Anime/DotHackSign'' and the American releases of the games.
* BunnyEarsLawyer: Tokuoka's weird outfit and habits hide the fact that he's actually a great programmer, who was able to copy Sieg's character data on the server from the school terminal and set up, with the help of Helba, the plan activated in the final OVA.
* ChekhovsHobby: Mai's training as a musician allows her to discern a tone that sounds whenever a Phase is about to show up. It was hearing this sound that forewarned her of Skeith's approach and allowed her to avoid the worst of the Data Drain.
* ClothingDamage: Non-fanservice example - Miss Asaba rips her sleeves and uses them to protect her hands (and Yuki's) so that they can slide down the elevator shaft.
* CoolCodeOfSource: The code that shows up is from the source code of the .hack games.
* CoolOldGuy: Tokuoka. Wears vibrantly bright shirts and stays relaxed even when getting beat down.
* DirtyOldMan: Tokuoka looks like this at first, especially to Mai's friend Masaya.
* EverythingIsOnline: Par for the course, given the series, but a standout example is that the security guards in part four can tell the heroes broke in by checking the ''vending machine records.''
** This is foreshadowed in Mutation, which has a news article about vending machines with online security.
* GenericName: How Tokuoka spots something is up with Ichiro Sato. The name "Ichiro" is extremely common for firstborn sons, and Sato is the most common family name. It's basically the Japanese equivalent of "John Smith".
* IdiosyncraticEpisodeNaming: "The Case of..." and then the character's name for the first three {{OVA}}s. The final OVA is called "Trismegistus", breaking the pattern.
* {{Leitmotif}}: Tokuoka has his own. It's a Jazzy saxophone piece with some quirky backup instruments.
* {{Meganekko}}: Yuki Aihara; it's brought up in universe by Miss Asaba at the end of the episode, who suggests that Yuki keep her glasses.
* MoonLogicPuzzle: In the third OVA, Tokuoka and Kyoko have to follow a trail of hints and clues all across the city. Often times the clues seem strangely arbitrary (references to Sadako from ''The Ring'', for example.) Fortunately, Kyoko is very familiar with the ''Epitaph of Twilight'', and her parents are familiar with the local myths and legends, so they are able to get through it.
* MysteriousProtector: A strange one. After the network crashing begins to cause a panic, a woman calls to Yuki and helps her to escape from the building. She only gives her last name, with a weak explanation of how she knows Yuki, and seems to have an agenda, but she only appears in the second OVA. Once they've escaped, she disappears.
* OrdinaryHighSchoolStudent: Mai. She's able to survive the data drain by Skeith without falling into a coma because of her musical training and sharp hearing, then gets involved in a complex and somewhat dangerous plot with Tokuoka.
* ScaryShinyGlasses: Happens to Ichiro/Bith in the 4th OVA. He's a reasonably nice guy, but he's a hacker.
* ShoutOut: To ''Film/TheRing'' in part 3 and to ''Series/CharliesAngels'' in part 4.
* ThemeTuneCameo: The Desktop Music from the game plays in part 1.
* UnusualUserInterface: Both played straight and averted. To play the game, Tokuoka uses what appears to be a [=PS2=] controller, but also has some kind of Virtual Reality headset on, which appears to respond to his head movements. When just using the desktop or the email systems, he uses an ordinary keyboard and monitor.
** It's a Face Mounted Display, also known as FMD or Neuro Goggles. It is very common in the ''.hack'' franchise, with the explanation for its invention being that it's more immersive. It doesn't actually control the game, it's just the visual display. There were also gloves being developed to complement them, which you find out if you follow the in-game "News" stories.