Mikuru is the daughter of Kyon's sister and haruhi's brotherThis would explain why mikuru acts and looks a lot like his siter but yet have a couple similarities to haruhi. i doubt that she's kyon and haruhi's daughter though since she doesn't treat them like they are her parents.
Mikuru moonlights as an AV actressShe's certainly got the looks to do it. The reason why she played with Kyon when he was looking at sexy pictures of her was because she's used to people liking her for her body. Her time travel scenario is just a huge cover-up for this, and the other Brigade members are unaware of the fact. When adult Mikuru reminiscences about the old days, she's really remembering her days as a porn star. Or she's starred in porn flicks with Koizumi (he's good looking enough to be in them, too). Who knows.
Mikuru is really Kyon's sister via Time Travel.This theory comes from the fact that both of them did a "knock on their head and stick out their tongue" gesture. They also share the same eye color and have similar facial structures; Kyon's sister's hair is a couple shades darker than Mikuru's, but Mikuru could have artificially lightened it in order to minimize her resemblance to her younger self. Mikuru also is remarkably at ease around Kyon, to the point of roughhousing and horseplay (if Haruhi isn't around), which seems to be quite at odds with her otherwise timid nature. She also suggests more than once that Kyon should not become "interested" in her.
Mikuru-chan present has never travelled through time until Episode 8, and it is Adult Mikuru who travelled BACK in time to meet Kyon.
Mikuru is Kyon and Haruhi's future descendantMake's more sense than his sister, and provides even MORE black humor.
Mikuru is close to thirty-five years old.Adult Mikuru is around a hundred.
Mikuru is, in fact, merely acting weak and helpless in order to get Kyon on her side.Itsuki explicitly theorizes this at one point. Kyon may not have actual god-like powers on his own, but he may have another, more subtle power which allows him to not only encounter plenty of other Haruhi-esque god-like beings, but also to influence them in a decisive manner. Mikuru is thus able to control the one who controls the gods. This, admittedly, relies a lot on random chance.
Mikuru's spaciness is because of her memory intentionally being "swiss-cheesed" to prevent paradox.She's the tool of the Future to change the Past. Having her memory change with each change would cause undue stress, so she's intentionally "dumbed down." Note her future self, who is also her Superior, doesn't have this problem in the slightest.
Mikuru isn't really as innocent as she seems.Think about it. Nobody can possibly be that shy involuntarily. This is supported by Adult Mikuru's feelings of nostalgia at the costumes into which she was forced; wouldn't she normally be terrified?
Asahina (Big) is actually from the same time period as Asahina (Small) because Asahina (Small) decided to stay in the past with the SOS Brigade and thus took The Long Way back to her time period.Think about it... The future inventor of time travel lives near Haruhi, and would likely know who Asahina is. He will likely ask Asahina in the future to help him form the time travel agency, and Asahina will arrange her younger self to be recruited and send her back in time to join the SOS Brigade.
Mikuru is in love with HaruhiAlas, Kyon's love is to forever go unrequited. Miss Asahina (big) didn't refuse Kyon's kiss because she didn't want to endanger the universe by way of Haruhi's jealousy. It's because she's just not into that. Apparently, all those "cosplay sessions" had an effect on her. The penultimate proof is in the above reference to Snow Mountain Syndrome, in which all the other characters have the objects of their affection show up in their rooms to seduce them, while Haruhi shows up in Mikuru's room.
Asahina is Drugging KyonKyon is constantly gushing over how everything she makes tastes divine, however, in several places (At the pool, etc) he mentions that he can't actually taste the food, but finds it divine regardless. This is because Mikuru is lacing his portions with LSD. She knows which ones Kyon will choose because Big Mikuru gave her a list. This is why Kyon's such an unreliable narrator, he honestly can't tell between what he's thinking and what he's saying, or even if he said anything at all. this is all a ploy to prevent him from realising his status as mentioned in any given WMG above.
Future Mikuru is not current Mikuru.In the anime, anyway, do we have any proof that she isn't just a body duplicate? They could have gotten hold of Mikuru's body (alive, on their side, both, or neither) and copied it, then gave future Mikuru everything they knew about the original Mikuru's time with Kyon. (For that matter, the original Mikuru may not be any more of a "real" human than future Mikuru, or even Yuki and Asakura.) She just picked something at random about herself that seemed sufficiently intimate. If Kyon had already seen the mole, it would "prove" it was her. If he hadn't, he would be curious enough to ask Mikuru about it, future Mikuru having successfully Tricked Out Time.
Mikuru's entire "organization" actually consists of herself...from various times. This is the real reason she keeps so secretive about her party (unlike Itsuki and Nagato): not to prevent some kind of paradox or anything but to prevent everyone from discovering the fact that she is the only human time-traveler in the past and future.
Mikuru's storybook is a horrible portent of things to come.Since Kyon and Nagato's stories were based on true events, there's no reason to think Mikuru's isn't either. Discounting the Snow White bits, Mikuru is telling the story of how Haruhi rose to take over the world. First she took control of Koizumi (the Tactician) group's resources. Then, with her the Seven Dwarves (her slowly expanding SOS army) she swarmed over the planet, achieving victory in every battle. Eventually she took over the world and retired somewhere with Kyon, leaving the planet in Koizumi's hands. Mikuru knows all of this, because it is mandatory in the SOS Brigade schools that run all education on the planet.
The only "proof" Mikuru has as to what she needs to do and her importance in the series is her own word, based on her own word, based on her own word...If Mikuru hadn't been here, everything would have turned out fine, though Tsuruya joining the Haruhi-tachi earlier would have resulted in more of a rough start to the SOS Brigade as she clashed with Haruhi. As it is, her presence settled before it even happened into a pattern that fed into itself to create a timeline where she would travel back in time to follow her own instructions. Yuki and Itsuki would have had the situation well in hand, along with Kyon, with all of the Mikuru-related things (including Bamboo Leaf Rhapsody) having either happened in a much more subdued way, or not happened at all.
In Mikuru's time, human's don't live on Earth.At some point, Earth will be rendered inhabitable. However, scientists saw it coming, and evacuated all humans to... Mars, or something, with enough supplies of oxygen, food and water to last several thousand years. This is why Mikuru doesn't seem to know anything about water whatsoever.
Anonymous is Mikuru's superiorThat is why Mikuru won't reveal anything about her superior, and it is the reason why Mikuru is such a Fanservice Girl.
Yuki and Itsuki are Mikuru' direct superiors.Yuki and Itsuki are actually more authoritarian, and they know about Haruhi, so they implanted Mikuru in order to study moe's effect on a sociopathic Jerkass Physical God.
Tsuruya is Mikuru's direct superior.If an organization of time travelers was willing to employ a 15-year-old girl, they'd probably have more than one. This explains why they're friends even though they're extremely different (particularly in outgoingness - Mikuru is very shy, while Tsuruya is the exact opposite), and also why Tsuruya seems to have had an idea of what was going on for a while. This particular WMG is inspired by a very short shot from the second season, with Tsuruya looking sinister in the shadows in the background while Mikuru tells Kyon that she doesn't agree with Itsuki's theories on Haruhi.
Mikuru is Kyon and Haruhi's daughterTime travel is never Exactly What It Says on the Tin, and Mikuru constantly gives mixed signals between her younger and adult selves. Young Mikuru is attracted to Kyon while Older Mikuru says she can't fall in love with him. It's a more extreme version of when a little girl says she wants to marry her daddy when she grows up, because due to time travel, Mikuru and her father are now the same age and he has all the qualities at this age that make him Mikuru's childhood fantasy. However, young Mikuru did this without telling her parents, thus explaining Older Mikuru appears briefly to tell Kyon exactly what he needs to hear in order to make him vaguely question if pursuing Mikuru is the right thing to do rather than acting on his Tsundere-ish relationship with Haruhi. The implication that Mikuru will have to leave him behind eventually is a pre-warning about the fact that eventually she'll go back to her own time, drifting out of Haruhi and Kyon's life as they get together. Eventually, when they have a red-headed baby girl, Haruhi will decide to name her after Mikuru after their childhood friend who moved away, and a few decades down the line, Kyon will finally noticed that Mikuru grew up to look like...Mikuru...and everyone will have quite the laugh over it all. Similarly, Haruhi's cosplay-rape tendencies that she honed on Mikuru will be repeated on her young daughter, then Haruhi sent Mikuru back in time, thus explaining why, despite her protests(because she's embarassed of being seen naked by a guy), Mikuru's pretty much used to it within an episode of her first appearance: she was raised that way.
Haruhi already knew Mikuru is her daughter from the futureAnd that is why she keeps manipulating Mikuru with almost absolute freedom. For the classified information thing...... it was only intended for other people besides Haruhi.
Kyon's sister is Mikuru's momAt some point in the future when she's all done with high school, Kyon's sister will marry someone with the family name Asahina and together they will have a daughter that they will decide to name Mikuru.
Mikuru isn't Japanese.She has red hair, and when looking at those yukata she said "So this is the traditional wardrobe of this country."
Mikuru is a CelestialItsuki and Kyon are the actual Time Travellers, and their "dimensional slider" abilities can also allow them to slide back and forth the timeline. The Celestials are in fact humans in the distant future, mutated by Haruhi's desire to express her anger. We all know how Haruhi expresses her anger: by raping Mikuru. (Yuki being a celestial is invalid since she isn't a result of Haruhi's angst). Celestials, being eldritch abominations who share Haruhi's ability of rewriting reality, can disguise themselves as being humans, and being the primal result of Haruhi's desire of being a dominatrix and having a Chew Toy, time-travelled back to the past just to please Haruhi while disguising it as the order of a classified information superior, who is of course... Haruhi. Also, maybe the reason why Itsuki defeats Celestials and prevents them from escaping Closed Space is to keep the celestials from ever going back in time and induce a sense of superiority in Haruhi, which means more controllability for Itsuki and Kyon.
Mikuru is JesusFirst, Haruhi-chan. Second, there is the possibility that Mikuru is Kyon and Haruhi's daughter. For a more biblical explanation: Haruhi seems to represent Judaism and the Old Testament, with a long history of esoteric magic, melancholy, and manipulation of people. Kyon, on the other hand, represents the New Testament, the Roman Empire (he's the majority and was responsible for the spread of Haruhiism), and modern day Christianity (it's the current definition of "normal") with the universalization of old doctrines (Haruhi) and the spread to more "normal" people. However, it is Mikuru, not Kyon, is Jesus (Kyon might be God of the New Testament, but is not Jesus). With Haruhi as the past, Mikuru represents the future (she's a time traveller after all) of Haruhiism (Kyon). She also suffers for Haruhi's sins (which parallels Jesus suffering for the Jews / OT God's sins). Kyon, being the new testament / rome / apostles in general, also had the desire to save Mikuru / Jesus (take Pontius Pilate trying to save Jesus from the Jews for example), but can't because of Haruhiism / Judaism / OT God's will.
Mikuru actually comes from a quite recent future.Haruhi's powers will cause a kind of Technological Singularity only one generation in the future, which will turn the old technologies utterly obsolete in a matter of few years. Mikuru is in fact first generation to have never have had any contact with the "old" technology, and the sheer amount of new development has caused the mainstream culture to largely lose interest in the recent past, save for the vital time travel services to keep history under control, which is why she is so helpless with contemporary tech despite of essentially being a time agent intern.
Asahina Mikuru is more capable than she appears.As far as her own time period is concerned. That she understands the mechanics of time travel enough to realize that Haruhi is the origin of the theory shows that she's not completely stupid. She's also able to completely grasp Nagato Yuki's technobabble with little effort, so long as it has something to do with spatial manipulation. Furthermore, we've never been shown anything in regards to her grades in school, so it's possible that she's much smarter than she appears. It's just that the vast majority of her knowledge is pretty much completely useless in the "present" time period (such as her lack of familiarity with modern technology), so she's effectively still more or less helpless either way. If there ever comes a time in which Asahina Mikuru is allowed to function in her native environment (i.e., the future from which she came), she may gain an astonishing level of competence for that duration.
Mikuru has a way of subconsciously influencing tropers.I have seen at least three separate occurences of a recognizable section of her name being inserted into long words in Suzumiya Haruhi no Yuutsu-related subjects three separate times. Two is a coincidence, three is a pattern.
Mikuru asked Kyon not to watch her the first time Haruhi started stripping her because she knew Kyon was unlikely to physically intervene.Mikuru was given a briefing on Kyon's psychological profile before embarking on her mission, and she knew that Kyon had an extreme reluctance, at first, to actively forcing Haruhi to not do what she wished. Therefore, Mikuru believed that Kyon would try to talk Haruhi out of stripping her without actually restraining the girl, which would leave Kyon doing nothing to help Mikuru as she's being stripped right in front of him. Rather than suffer that embarrassment, Mikuru asked Kyon to leave rather than make an empty gesture. (Okay, said like that, it looks like option b, Mikuru is a spazz, is more likely. Or the even the somewhat unlikely option c, Mikuru is secretly letting herself be abused because she knowingly and deliberately accepted a mission to go back in time and become Haruhi's pet in the hope that she would gain some influence on the reality warper.)
Mikuru is from 200,005,600 years in the future.Haruhi says to Kyon in Disappearance: "Come back in 200,005,600 years if you want to sneak a peek at Mikuru's underwear!" Things Haruhi say tend to turn out to be randomly true, and remember that Mikuru's not allowed to be in a relationship with people not from her time period, so presumably Haruhi is saying that if Kyon were to exist that many years into the future then he would be allowed to be in a relationship with her. It's likely that she's not from the near future, because apparently in her time period, boats don't use buoyancy to float, and that's not going to change for quite a while, so the number Haruhi gives is plausible. However, that brings up questions like "Has evolution stopped well enough that humans remain the same, even two million years into the future?" "Did human evolution stop when Haruhi eventually dies?" "What happens to Haruhi in the future?.
Mikuru is Kyon and Mikuru's daughter via Time Travel.Mikuru is Kyon's daughter and granddaughter and great-granddaughter...
Mikuru was born into poverty.This is why she's so useless with current technology and history: her access to education was severely limited. Surely in the future there might be something in place to give all people basic educations, which is how she knows of a few things, but not a whole lot. The reason Mikuru interns at the Time Travel Agency is to try to earn enough money to escape, and get a chance to go to school (archaic as the lessons may be) in the process.
Time travelers are rare because?Why are time travelers so fnording rare? We've seen four interfaces and at least half a dozen espers. The interfaces and espers both claim that there more of them running around out there. But so far we've got exactly two time travelers and the shortage is so acute that Mikuru has to touch herself to get things done. So why is this? Note to the future: If your present reality does NOT include billions of human beings, please time travel to change your timeline rather than reinforce it.
A future Haruhi is Mikuru's superior.Mikuru has already said that Haruhi will have founded her organization so what if Haruhi is still around giving orders to adult Mikuru to give orders to teenage Mikuru?
The time stasis from Tanabata was to freeze in the timeline.In order to make a change in the past stick, the time travelers have to live out the period after the change. Otherwise it either gets undone or drifts off to a slider dimension.
Haruhi wants her own Mikuru doll because John Smith had one.
Mikuru was chosen to seduce Kyon.They searched the entire population of Earth to find the right person and they trained her against their historical models.
Mikuru is a sliderThe Melancholy of Mikuru Asahina reveals that there are multiple futures. She came from one possible future into present time to ensure that her future will occur. Therefore its possible that the present she is in now is headed on a different path, and she slid into the dimension to change that.
Mikuru is a SCP agentBecause, when she is speaks ██████ and ██████ so ██████ ███████████.
Fujiwara is suffering from a Cynicism CatalystFujiwara grew up with the loss of his big sister Mikuru and once he began time traveling he discovered an alternative timeline in which Mikuru survives, but as an only child. So he won't rest until he finds the one who killed her. Pity he didn't start that search in the mirror.
Mikuru and Fujiwara are not from different futuresFujiwara just hasn't been born yet in the time Mikuru (big) comes from and medical technology has improved to the point where she didn't age enough for him to tell the difference.
There was a change in the timeline that resulted in Adult Mikuru's change in personalityFrom what I've seen (as I have not yet read anything past Disappearance), Adult Mikuru is manipulative, but she did not seem that way in her previous appearances. (I.E. giving Kyon a hint to get out of the Closed Space at the end of Melancholy, she could have just let Yuki tell him the answer, and apologizing to Yuki for the trouble that her younger self caused). With the appearance of Fujiwara, the timeline changed and her personality changed because of it.
Mikuru is the member who will ultimately end up betraying the Brigade if such a situation were to occur.As opposed to the widely theorized Itsuki. She's emotionally attached to Kyon, and values him (as either a friend or romantic interest, your pick) and as a result will do her best not to betray him personally; perhaps even protect him in such a situation. Everything Itsuki has said about her in the past is correct, as although she herself may not be particularly malicious, the organization she works for is.
Mikuru is from the future, but from a destroyed time plane.Or rather, one that will be destroyed if she doesn't fix the past. An event that has happened or will happen at some point in the story has to be stopped or changed by Mikuru (whatever it may be) in order to protect her future, as this event is what caused her time plane to disappear. Otherwise, she has no future to return to. It isn't just a case of observing, or preventing a situation that will either slightly or totally modify the future like a fight between Haruhi and Kyon (e.g. in Sigh); she must actively stop a pre-determined event from taking place in order to actually CHANGE the future, ultimately protecting it.
The SOS Brigade will evolve into Mikuru's superiors.