[[caption-width-right:236:Kuroha Neko, the one to be blamed for everything.]]

For 10 years, Ryouta Murakami has been tormented by the death of his childhood friend Kuroneko, whom he had been really close to. The guilt he feels because of her death had 2 effects on his psyche: motivates him to fulfill [[ThePromise a childhood promise he made with with her to show aliens do exist]] (at his 16 years of life, he's already third-ranked in school and is on fast track to become a NASA researcher, with some thanks to his superb PhotographicMemory), and left him with a deep inability to communicate with and understand the opposite sex.

One day, a girl who looks exactly like Kuroneko appears before him. Her name is Kuroha Neko, and from then on, a story of horror, experiments, human communication, and despair begins.

''Kiwaguro no Brynhildr'' (or ''Gokukoku no Brynhildr'' going by the furigana spelling; officially translated as ''Brynhildr in the Darkness'') is a manga by Okamoto Lynn. It keeps the science-fiction horror tone and massive {{Gorn}} [[Manga/ElfenLied of previous works]]. An {{anime}} adaptation has also been green-lighted, and will air [[Spring2014Anime as part of the Spring 2014 season]]. The animation studio behind it, however, is Arms, the same ones who did ''Elfen Lied''.

Crunchyroll is streaming the anime, which can be [[http://www.crunchyroll.com/brynhildr-in-the-darkness viewed here]] for people living in the following areas: U.S.A, Canada, United Kingdom, Ireland, South Africa, Australia, New Zealand, Finland, Norway, Sweden, Denmark, Iceland, Netherlands, Turkey, Latin America (Central and South America including Caribbean), Spain, Portugal.

''[[YouHaveBeenWarned Cautious editing/viewer warning]]'': While the manga is {{Seinen}} and has a public run, it is '''very graphic'''.
!This manga provides examples of:
Other manga by Lynn Okamoto:
* Manga/ElfenLied
* Manga/{{Nononono}}
* AbusiveParents: Ryouta's mother is rather harsh, but is averted since she hasn't done anything that could be considered abusive.
* AccidentalPervert: Ryouta grabbed Kuroha's boobs once by accident. Not to mention what he did to Kazumi in the outdoors bath.
* ACupAngst: When Kana is protesting Ryouta groping her as an excuse to move her out of the burning house in episode 3, he says that she doesn't have anything up there anyway. She doesn't like that remark.
* AdaptationExpansion: Which is a ''[[CrowningMomentOfAwesome complete]]'' [[InvertedTrope Inversion]] when compared to the anime of ''Elfen Lied''. For example, the test comparisons and places of Ryouta are not mentioned until Chapter ''55''.
* AndIMustScream: Milder example with Kana who is like this due to experiments -- she can only move her fingers a bit to type on her keyboard to communicate. She does, however, [[RunningGag scream whenever her food gets put in a blender]].
** [[spoiler: it is suggested that she can move, but doesn't as it will for some reason upset Neko.]]
* AnyoneCanDie: While no critical characters have been killed off, there have been many side characters that have.
* BadassNormal: Armed with only his PhotographicMemory, Ryouta has proved himself time and again to be as dangerous as the [[BadAss Magi]][[MagicalGirl cians]] that he and the girls must fight off on a frequent basis to stay alive to the point that he is the defacto [[TheStrategist strategist]] that comes with up with the plans that save the day.
* BilingualBonus: The ''Harnessed'' is the button-like thing on the nape of magic users. [[spoiler:Due to how things are transliterated to Katakana, it's easily possible to miss that the real transliteration is ''her nest'' (which gets written in the same way), an obvious reference to where resides the parasite inside the magic users' bodies. Interestingly, according to the translators, "Harnessed" [[GratuitousEnglish in English]] was the original name.]]
* BloodFromTheMouth: Kana starts to do this in episode 3 after Kuroha explains to Ryouta about their "death suppressant" pills. She mentions that if they don't take the pills every 30 hours or so, they'll start to bleed. And after 35 hours, their internal organs start to melt and they die.
* BodyHorror: Magic Users [[ItMakesSenseInContext melt]] when they go too long without taking the medication. And that is only the final stage. Before that, they start to [[{{Gorn}} bleed all over]], [[{{Squick}} their bodies break down, and even their internal organs shut down before that happens]].
* BookDumb: Kuroha is unable to do simple multiplication despite being in the same class as Ryouta. He is understandably baffled at how she's even in that school if she can't do math. She also can't read very well either, and he tells her that her cover is going to get blown if she's trying to blend in this way.
* BreakTheCutie: All the magic users come prebroken for your convenience. You could think that further breaking is on the menu and we wouldn't blame you for it, anyways.
* CaptainErsatz: Hello, [[{{Manga/ElfenLied}} Nozomi]]!
* CassandraTruth: Kuroha tells Ryouta various things, such as not to miss the last bus, but then later tells him to stay at the observatory. Naturally he doesn't exactly believe her, and wonders what [[TemptingFate could possibly happen]] in the rain out in a remote road near a mountain. Then a mudslide occurs...
* ClothingDamage: Kuroha suffers some in episode 3 during her fight with Saori. [[spoiler:Aside from the obvious FanService, this also allows Ryouta to see the three moles his friend Kuroneko had, and he then realizes she was still alive. At least until Saori turns her into a bloody mess.]]
* ClusterFBomb: Kana. ''Seriously''.
* CloudCuckoolander:
-->'''Ryouta''': ''TWO TIMES TWO?!''\\
'''Kuroha''': ''A squirrel?''
* [[spoiler: CosmicHorrorStory: It's implied that the leaders of the research facility are not from Earth. There's also enough evidence to suggest that the parasite is actually an alien life form.]]
* CryCute: In episode 2, when Ryouta mentions the third piece of cake he brought was for him, Kuroha starts to shed tears. Kana then berates him for making her cry, and he decides to let them have the cake instead.
* DetachedSleeves[=/=]OperaGloves: Part of Kuroha's school uniform.
* DoesntKnowHerOwnStrength: When Ryouta challenges Kuroha to an arm wrestling contest, she easily defeats him. However, she slams his hand rather hand onto the table, as he's wincing in pain afterwards. He then gropes her arm and wonders how she managed to do that.
* DoesThisRemindYouOfAnything: In order to get inducted to the research facility, you must possess high knowledge and have low contacts. They can prove the former with agreeing with the college of graduation, but the latter is done with incredible levels of spying (for example, they know [[TheInternetIsForPorn if you've gone to porn sites]]). Yuki believed that this was [[StalkerWithoutACrush one thing]], but the reader knows that it is [[CloakAndDagger the other]].
* DoYouWantToCopulate: Kazumi comes right out and asks this of Ryouta.
* EldritchAbomination: [[spoiler:The horrendous thing that remains when a magic user is destroyed with her Harnessed's down-left button gives all vibes of this. Might be an alien life form that parasites the magic users' bodies and gives them their powers, but this is unconfirmed.]]
** [[spoiler:That ''thing'' that resides in a Magic User has multiple eyes, a jelly mass, is apparently ''sentient'', and most likely alien. If this is not Eldritch, then what is?]]
** [[spoiler:The Initial Sorcerian is something not from this world, but has been tested for the past 20 years. Its DNA and overall composition supports this, but the exact details of what it can do are left ambiguous.]]
* ElegantGothicLolita: Kana, complete with OjouRinglets.
* EverythingTryingToKillYou: Between the TheMenInBlack using Magic Users trying to capture and remove others, rogue Magic Users attempting to kill anyone just for the sake it, and several times the ''environment'' trying to kill the main characters, nobody is safe.
* FanService: ImprobablyFemaleCast with a guy who is not comfortable around women; of course there is going to be FanService.
** FanDisservice: The ''first two pages'' is Ryouta stabbing Kuroha with lots of blood flowing in full color. By this, you know that FanService will not be plentiful. [[spoiler:In chapter 3, we learn that Kanade, another escaped magic user, has been captured. She's shown strapped face-down on a table, naked.]]
* FateWorseThanDeath: What the Magic Users are told about the third button on their harness. Note that this is ''implied''.
* {{Foreshadowing}}: This manga doesn't even try to hide the idea that Kuroha Neko might be Ryouta's childhood friend Kuroneko.
* ForScience: Every scientist so far (with the exception of Yuki) has only the desire to continue their work just because they think it is interesting. Kougorou is the good variant of this trope, but he is slightly crazy in his normal work and very hard to convince.
* {{Gorn}}: Okamoto indulges in this each time more and more; just compare the post-accident Ryouta in episode 1 to [[spoiler:the fight with Saori in chapter 9]].
* HairDecorations: Kazumi wears a headband.
* HandicappedBadass: Although Kana is paralyzed and can only move her left hand slightly and swallow food, she still has the ability to foresee future events with the help of a computer which helps Kuroha out quite a bit when saving people.
* HeroicSacrifice: Kuroha intended to do one in episode 3, so that Ryouta could find the pills they need to survive, and allow at least Kana and Kasumi to live on.
* ImMelting: What happens when the harness of a magic user is removed [[spoiler:and is first seen in chapter 3/episode 2 with Kanade.]]
* ImprobablyFemaleCast: All of the magic users shown until now are teenage girls.
* LaserGuidedAmnesia:
** [[spoiler: Everytime Kuroha uses her powers, she loses a part of her memory.]]
** [[spoiler: Ryouta is on the receiving end of this where the MindRape user erases all of his memories, but it's revealed later that her power doesn't work on him due to his eidetic memory.]]
* LethalHarmlessPowers: Ryouta openly asks how someone with the ability to change places with anything could kill someone. Kana responds by stating how she could jump off a cliff and switch places with her target so they plummet to the ground.
* LeotardOfPower: Saori wears one.
* LudicrousGibs: Used in episode 3, [[spoiler:when Saori seemingly does this to Kuroha at the end of the episode.]]
* LuminescentBlush: Kuroha displays these occasionally.
* MadeOfPlasticine: just like in ''ElfenLied'', an offensive power hitting a human is not a pretty sight.
* MajorInjuryUnderreaction: In the beginning of episode 3, Kuroha shows up to school in a lot of bandages. When Ryouta inquires what happened, she simply claims she had a cold. [[spoiler:Kuroha later explains they have to take a death suppressant pill every 30 hours or they'll start bleeding, and after 35 hours their internal organs melt and they die. She was attempting to wait until the last minute to take them, but as Ryouta finds out after the opening credits, she took too long this time and was on the floor bleeding.]]
* MaleGaze: Used a couple of times in the anime, such as the focus on Kuroha's legs when she's running towards the scene of a predicted accident in episode 2.
* MagicFromTechnology: Kuroha tells Ryouta she's a witch. He naturally doesn't believe it, and asks her how she got so strong and was able to slice a boulder in half with her bare hands. She then turns around and shows him something sticking out of the back of her neck.
* TheMenInBlack: The common dispatch the science facilities use to capture and/or kill Magical Girls.
* MindRape: Nanami. From wiping out their memories from until the age of five to implanting memories to believing a guy raped his sister who doesn't even exist. This ranges from HilarityEnsues to FridgeLogic.
* MoodWhiplash: Well crazier than ''Elfen Lied''. In the anime opening, the girls are shown bloodied around a normal background, but then the background is swept away to a more desolate looking scene, while the girl then gets cleaned up and looks normal. The show also switches back and forth from going to school, to more action-oriented things.
* MundaneUtility: The one that can teleport used her ability so she wouldn't be late to school. Note she can only use this once per day and is supposed to be in hiding. Ryouta immediately calls her out on doing such a thing so carelessly.
* MysteriousTransferStudent: Kuroha's arrival sets the whole plot in motion.
* NeverFoundTheBody: While Ryouta was told Kuroneko was killed in the accident at the dam, he never got to see her body for himself. Hence why when Kuroha shows up and bears a striking resemblance to her, he can't help but think that it's his old friend, despite her claiming she's not Kuroneko. [[spoiler:When Kuroha suffers some ClothingDamage in episode 3, he is able to see the three moles near her chest, and realizes Kuroha is Kuroneko.]]
* NiceJobBreakingItHero: Kuroha attempts to boil some water in episode 3, but causes the house to catch on fire instead. [[spoiler:Worse, the death suppressant pills they were supposed to take every 30 hours also burned up, and Kana's last dose was yesterday. She starts bleeding from her mouth, but tells Kuroha not to worry about it.]]
* NoseBleed: Kuroha suffers one at the end of episode 2, but it's not made clear if it's being used for this trope or because of a side-effect of her powers. [[spoiler:Episode 3 reveals they have to take death suppressant pills every 30 hours, or they'll start bleeding, and after 35 hours, their internal organs melt and they'll die.]]
* NothingIsScarier: The Magic Users are told that on their harness the first button cancels their magic for 1 hour, the second button kills them, but are not told what the third button does. They are only told it is a FateWorseThanDeath.
* NotSoAboveItAll: Ryouta catches Kuroha singing to herself in episode 2 when he tries to find out her address to give her some paperwork from school.
* PerpetualPoverty: Kuroha and Kana are hiding in an abandoned village, and have no money to buy food or other basic necessities. So when Ryouta shows up with some food and cake, both girls are ecstatic about it.
* PhotographicMemory: Ryouta has a really good eidetic memory; he ''never'' forgets anything, and it also gives him incredible powers of observation and deduction. For example, one part has him trying to remember writing in German from a building; he remembered the entire thing at 100% accuracy in the span of a few minutes. [[spoiler: It also makes him immune to LaserGuidedAmnesia]].
* [[spoiler:PosthumousCharacter: Since Nanami knows that Ryouta has photographic memory, she rewrote his to include her own memory. It "took some space" for her to fit but she will visit again.]]
* RandomPowerRanking: The Magic Uses are ranked by how many powers they have and how skilled or powerful it is. If they are not strong enough, they are disposed of. It is because of that this series started, as the Magic Users escaped a disposal transport.
** RankInflation: To begin with, ranks are described as ranging from B to AAA (with A being a step up from BBB,) but in chapter 26 the existence of a rank S Magic User is alluded to but what sort of power involved is unclear. [[note]] The overall vagueness of what power this magic user can have makes this go either way between BeyondTheImpossible and RankInflation. For background, a high-ranking Magic user was able to eviscerate anything withing a six-meter radius, as well as turn back time by one minute, and was demonstrated in the manga very clearly, but this user is not even close to Rank S. [[/note]]
* ReadingsAreOffTheScale: Ryouta has a memory so good, he's averages in the ''top 2 percentile''. This is apparently known by many of his classmates. [[spoiler:When Kuroha ends up beating him in the midterms, ''everyone'' gives a FlatWhat at the results as if it was something impossible, and gave Ryouta ColorFailure. Kuroha's memory is so good, that, if she wasn't losing it all the time, she can effectively beat ''photographic memory''.]]
* RuleOfSymbolism: NorseMythology gets thrown around by the researchers. The closest to any sort of explicit information is "Skadi", a AAA magic user with the ability to see, predict, and ''[[UpToEleven interfere]]'' with the future, at the cost of her life. Another one is "Drasill", which is briefly mentioned twice, never explained entirely, and said to have some kind of horrendous power. One head researcher states that if 1107 (the number for Kotori) is not captured, it would initiate TheEndOfTheWorldAsWeKnowIt via Drasill.
* SacrificedBasicSkillForAwesomeTraining: Sort of. From what Kuroha has mentioned, the girls who are turned into witches seem to have almost superhuman powers, but are also horribly abused and not allowed to learn basic things like reading and math. She also says they usually die young, which may also explain why they're only teens, and she feels she doesn't need to know stuff like that anyway, never mind that she's attending a high school with an education equivalent of an early grade schooler.
* ScrewDestiny:
** Ryouta has this outlook when Kuroha tells him about his future in the first episode. If not for her timely arrival, he would have died.
** Kuroha also tries to prevent people from dying if she can do anything about it. While some of her interventions require some rather brute force, such as saving Ryouta from a giant boulder, others are a little more vague as to how to resolve it, [[spoiler:such as the woman in red that they bump into on the way to save a woman in red from getting hit by a car in episode 2. At first they thought they were too late when they saw the crashed car, but Ryouta realizes that minor incident earlier delayed the lady enough that she wasn't in the path of the car as Kana had foresaw, thus indirectly saving her life.]]
* SecretlyWealthy: Ryouta's Uncle, who has a lot of money in several accounts due to being very good in the stock market.
* {{Seers}}: Kana.
* ShoutOut: At the end of Chapter 10, the island visible from the beach Neko and Ryouta are standing on will look awfully familiar to fans of ''Elfen Lied''[[note]]The island is Enoshima, which was significant to the plot of both the anime and manga[[/note]].
** "What's [[StreetFighter Tetsuzanko]]?"
* [[spoiler: SomeoneToRememberHimBy: More like Someone To Remember ''Me'' By. Kazumi eventually decides that she wants to make a child with Ryouta as to leave living proof of her existence.]]
* SpiritualSuccessor: Should be [[Manga/ElfenLied pretty obvious]] by now.
* StepfordSmiler: Kazumi, enough said.
* SurvivorsGuilt: Ryouta is traumatized by the accident he had with Kuroneko years earlier when they fell off a pipe while traversing a dam. As a result, he vows to find the existence of aliens for his friend, and has trouble associating with girls as a result.
* SuspiciouslySpecificDenial: In a FlashBack at the beginning of episode 2, Ryouta asks Kuroneko if she's looking forward to going to the beach on a field trip. She says she isn't, but he immediately calls her out on wearing an inflatable tube while stargazing.
* TechnoBabble: Ryouta's explanation of RSA[[note]]the de-facto example of real-life asymmetric encryption[[/note]] and the processes within organic chemistry[[note]]the discipline that is used to create and discover real-life compounds and medicines[[/note]] leaves ''a lot'' to be desired.
* TemptingFate: In the first episode of the anime, Kuroha warns Ryouta at first to catch the last bus near the observatory, but then tells him not to catch it and to instead stay where he's at already for the night. He says that the weather should be clear, only to then have it start raining. And he also decides to leave and deliberately miss the last bus, figuring he probably wouldn't be a victim of a crime in such a remote location. He then wonders what could happen locally, then notices a mudslide coming down on him, which also traps him while a giant boulder falls.
* TheyWouldCutYouUp: Why Ryouta and the escaped magic users don't simply go public. Ryouta claims they would simply end up back on the experiment table. Which is odd considering the lengths the antagonists themselves go to to keep ordinary people finding out about the magic users, but then, if the central conflict could be resolved that easily, [[AnthropicPrinciple there would be no story]]. He also overhears Kuroha telling Kana that if he did try to befriend her, they'd go after him too. Despite that, Ryouta still takes the risk of trying to befriend her and the other witches he runs into.
* [[spoiler: TimeMaster: Saori's second power is to revert time back for one minute. However, it causes her to lock up.]]
* {{Tsundere}}: Kana appears as one, even though she's crippled and can only talk with the help of a computer and her left hand.
* TransferStudentUniforms:
** Because Kuroha never attended school, she wears a ''self-made'' uniform (see page image).
** [[spoiler: Kazumi's]] uniform consists of clothes she found at the abandoned village.
* TruthInTelevision: In chapter 6, it's revealed that Kazumi's magic is her capability to factor very large integers with ease, and that makes her capable of breaking the security of many systems. Then again, the [[TechnoBabble explanation and theory exposed]] in the chapter would make mathematicians and cryptographers cringe.
** ShownTheirWork: On the other hand, a similar situation in which Ryouta asks Kougorou, a head chemist at a research facility, on the process how the "anti-death pills" are made (this field is known as "organic chemistry") is done using ''extremely basic'' terms, which is TechnoBabble at best for those who may or may not know the topic itself. It's useless to explain a concept that would take several pages when the audience only needs to know the basic idea to understand. Plus, [[{{Justified}} we're talking about a kid who's listening to a topic very outside of his field of research and he only heard about it briefly, if barely at all]]. [[GeniusBonus You may need to know some of it already in order to understand the entire concept]].
* UndeadTaxExemption: Kuroha can only attend school because she knows a ''very'' skillful hacker. On top of that, nobody there seems to bat an eye that her outfit isn't the girl's standard school uniform.
* UnprovokedPervertPayback: Kana insists that Ryouta wants to molest her ''every single time'' he's around; she even does this when he [[spoiler: carries her out of a burning house. She gets over this in Chapter 46]]
* UnskilledButStrong: Kikako, the second AA+ magic user we see. Her beam powers are capable of decimating chunks of land, but she can only shoot them in a straight line with a little time lag.
* UnwantedHarem: In the [[{{Deconstruction}} straightest way possible]]. Ryouta doesn't want more girls to be in danger, and every new girl just adds too many problems to the mix. Especially since every new addition to the group [[spoiler: puts more strain on their stockpiles of the pills that keep the girls alive.]]
* WhamEpisode: [[spoiler:In episode 3, Kuroha is seemingly turned into LudicrousGibs right in front of Ryouta by Saori, another witch.]]
* WhamLine: This manga just loves these.
* WhatKindOfLamePowerIsHeartAnyway: One of the Power Users seems to see her ability of Switching her placement with another as this, especially since she can only use it once between breaks.
** Later becomes HeartIsAnAwesomePower when she is able to use it to capture a AA ranked Power User by handcuffing herself and switching places with it so she would captured. Another Power User even comments on how it is a LethalHarmlessPowers if she decided to switch with someone after she jumped off a cliff.
* WhatIsThisThingYouCallLove: Kuroha clearly has feelings for Ryouta, but does not understand what they are. She even questions why her heart isn't beating fast like it does when she touched Ryouta's hand when her hand was held by another guy.
* YouGottaHaveBlueHair: Kuroha's hair is either dark blue or black while Ryouta's hair is light green.
* [[spoiler:YouHaveOutlivedYourUsefulness]]: How the research facility deals with scientists who leave the facility. They give a GPS tracker, a set list of guidelines, and a ride out. [[spoiler:Then they kill the scientist.]]
* YouNeverAsked: The magic user that teleports has a nasty habit of not giving Ryouta extremely important information until he himself has already come to the conclusion. Though in a rare case it isn't because she is a JerkAss but because she is TheDitz.
* ZettaiRyouiki: Kuroha wears thigh-high black stockings to a short dress as her school uniform.