[[quoteright:320:http://static.tvtropes.org/pmwiki/pub/images/blue_drop_hagino_mari2.jpg]]
[[caption-width-right:320:Hagino & Mari]]

'''''Blue Drop''''' is a series of manga stories by Akihito Yoshitomi in which [[VichyEarth Earth has been conquered by the Arume]], an alien race which is very much [[HumanAliens human in appearance]], but [[OneGenderRace consists only of females]]. Consequently, they are by and large homosexual and are attracted to earth women, which leads to a lot of depictions of [[GirlsLove lesbian sexual behavior]]. An anime series was released in 2007 that takes place one thousand years before the manga and describes the events leading up to the Arume invasion. The anime's emphasis is more on character development, whereas the manga tends to be more explicit and often crosses the line towards {{Hentai}} (although it's generally more [[FanDisservice creepy than erotic]]).

The manga consists mainly of one-shot stories, presented in two series, describing the struggles of human society with the Arume in charge. The main recurring character in the first series is Yui, who is a human/alien hybrid and a member of the earth resistance. An important theme is the Arume's use of children to fight the semi-sentient remnants of their biological weaponry in the earth's seas. The second series , ''Blue Drop - Tenshi no Bokura'' (Angel's Men), adds some [[GenderBender gender-bending]] to the mix and often contains very graphic (and very horrifying) sexual scenes and themes. ''Blue Drop's'' third {{manga}} is a short, romantic story called ''Maiorita Tenshi'' which chronologically is set between the anime and ''Tenshi no Bokura''. Lastly there is the {{manga}} ''Tenshi no Itazura'' (Angel's Prank), the shortest ''Blue Drop'' work being only three chapters in length.

The anime series is called ''Blue Drop - Tenshitachi no Gikyoku'' (Angels' Play) and describes the antics of Hagino and Mari. Hagino is the commander of an Arume battleship; Mari is the sole survivor of a disaster caused by that ship five years earlier. The story focuses on the gradually intensifying relationship between the two girls, set against the threat of the Arume invasion and Hagino's rising doubts about its purpose.

The subbed version of the {{anime}} currently has a [[http://www.youtube.com/show/bluedrop free legal stream on YouTube]] courtesy of the animenetwork, although restricted to certain countries.

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!!Tropes:
* AlienInvasion
* AliensMadeThemDoIt
* AnimalMotifs: There are terns appearing throughout the anime, including in the dorm's stained glass windows. And then there's [[SpaceWhale Hagino's spaceship]].
* AppliedPhlebotinum: the Emul Force and the "thought-arresting weapons" that it powers.
* ArtificialHuman: The Arume create synthetic children as living bombs.
* BittersweetEnding: [[spoiler:The anime ends with Hagino pulling a SenselessSacrifice at the beginning of the Arume Invasion. The Arume win. However, the Distant Finale 30 years later implies that humanity is on its way to a truce with the Arume]].
* BleachedUnderpants: compared to the second manga series
* BlueAndOrangeMorality: The Arume aren't completely out there, but their sense of morality definitely doesn't jive with humanity's. Specifically, using ChildSoldiers (Volunteer, or so they claim) for [[SuicideAttack suicide bombing]] because it's "beautiful" and being grossed out by males.
* BookEnds: The anime starts and ends with [[spoiler:Michiko in a shuttle on her way to a peace talk with the Arume]].
* BridgeBunnies: Tsubael
* [[spoiler:BuryYourGays]]: [[spoiler:Hagino dies, right after she and Mari confess to each other. Who would have seen ''that'' coming?]]
** In ''Maiorita Tenshi'', [[spoiler:this trope gets [[SubvertedTrope subverted]] by Ai in the last chapter.]]
* CannotSpitItOut: Hagino, repeatedly.
* CensorSteam: Used in the anime during a kiss.
* ChivalrousPervert: Yui
* ConspicuousCG: One word: {{GONZO}}
* CoolButInefficient: Tsubael uses a robotic bird to commmunicate with Hagino. Cell phones, anyone?
* CrapsackWorld: If you're a MagicalGirl, you're a bomb disposal unit. If you're a schoolgirl, you're little more than a sex slave. If you're a guy, you're used as a lab-rat for transgender experiments ''if you're lucky''.
** If you're not so lucky as to be part of an experiment, you're an animal, a third-class citizen treated like freed Africans in Antebellum America- not a slave, but only just.
* CreditsRunningSequence
* DatingCatwoman: In the manga, Yui the Half-Arume rebel and Misato the Arume scientist.
* DefrostingIceQueen: Hagino shows a mild variety of this.
* DiscountLesbians: The Arume and their half-human offspring.
* DisturbedDoves: Actually, lots of seabirds.
* DramaticWind
* ElaborateUniversityHigh
* EvenTheGirlsWantHer: Hagino, and, in her {{Bifauxnen}} role in the play, Akane.
* EvilVersusEvil: In ''Tenshi no Bokura''. The Arume (simply batshit insane) versus [[spoiler:Yoshimura]] (batshit insane and concertedly sadistic). Weirdly, they seem to be at peace by the end despite wanting to wipe out each other's sex.
** It should probably be noted that there are hints that [[spoiler:Ma-chan]] and [[spoiler:Yoshimura]] are actually doing a tag-team {{plan}}. This actually may qualify as FridgeBrilliance as this does seem altogether ''too'' likely be the only way to [[spoiler:restore the Arume's men]] without a certain segment of the Arume throwing a SpannerInTheWorks.
* FanDisservice: The Arume's sexual habits are often rather ... [[{{Squick}} weird]], to put it mildly.
* FanService: Much, MUCH more in the manga, but the anime has some bikini shots.
* FlowerMotifs: The episode titles in the anime.
* GenderBender: In the manga ''Tenshi no Bokura'' only. Played for drama, tension, and horror rather than laughs, [[spoiler: then turns into an [[SubvertedTrope subversion]]- its just a girl brainwashed to THINK she had once been a boy.]]
** [[spoiler:Not so much as "think" she was a boy. The girl had the boy's memories and personalities downloaded on top of hers, and over the course of the series, their minds kinda blended together making a new one with the boy's personality being dominant.]]
* GlowingEyesOfDoom: Hagino
* {{Gonk}}: Does Hiroko really have to be ''that'' large?
* GratuitousEnglish: Hiroko's suspiciously apropos "KEEP WEIGHT" shirt.
* HalfHumanHybrid: The Arume sometimes interbreed with Earth women.
* [[HandsomeLech Handsome... er, Beautiful Lech]]: Kisagi from ''Tenshi no Itazura''.
* HotForStudent: When the Arume run schools, many of them seduce their female students. In ''Tenshi no Bokura'', they had a school that was, essentially, their seraglio, the girls having pretty much been raised to think that such was the norm.
* HumanAliens
* IdiosyncraticEpisodeNaming: The episode titles are [[FlowerMotifs scientific names of flowers]].
* IfItsYouItsOkay: In the original {{Manga}}, Ami feels this away about Yui after Yui rescues her. Also [[{{Subverted}} subverted]] in ''Tenshi no Bokura'' with Kotoko, who thinks she can fall in love with Shouta but can't get past the fact that he's a guy.
* ImperialStormtrooperMarksmanshipAcademy: ''Tenshi no Bokura'' is an egregious offender of this trope.
* InterspeciesRomance
* IntertwinedFingers: Evidence of Hagino and Mari's RelationshipUpgrade.
* InvisibleToNormals: Mari is the only one who can see [[spoiler:Tsubael's holographic projection.]]
* JumpingTheGenderBarrier: ''Tenshi no Bokura'', which does it with a technically heterosexual couple due to lesbianism and a male mind upload into the girl- the barrier is jumped when the upload starts wearing off.
* KissingDiscretionShot: Combined with the above-mentioned {{censor steam}}.
* LeftHanging
* LoveAtFirstPunch: Well, a strangling-attempt...
* LoveableSexManiac: Yui
* LuminescentBlush: Everyone, incessantly. Everyone with human blood at least as the Arume have no shame. Hagino forms an exception, seeing how cautiously she treats Mari.
* MacrossMissileMassacre: At the most ridiculous, with FIGHTER PLANES.
* MarsNeedsWomen: As if the Arume didn't have plenty already. To make matters worse, ''Tenshi no Bokura'' reveals that they actually ''need'' men in order for their species to not die out in the near future. They even invaded ''for the sole purpose of getting our men''. Then they got cold feet at the last minute and took our women instead, as they are much hotter albeit useless for stabilizing the Arume population dynamics.
* Creator/MiyukiSawashiro: She voices Hagino.
* MoodWhiplash: The anime bounces between SliceOfLife and SpaceOpera.
** In fact the anime, the original ''Blue Drop'' {{Manga}}, and ''Tenshi no Bokura'' might as well all be from different series considering the sharp changes in tone.
* NoSocialSkills: Ai from ''Maiorita Tenshi''.
* OlderThanTheyLook: Hagino looks about the same age as Mari, but is likely quite a bit older.
* OminousFloatingSpaceship During the invasion
* OneGenderRace
** However, not originally: according to ''Tenshi no Bokura'', their men died out. [[spoiler:But not before one of them knocked up a human woman, leaving behind a line that could restore the Arume's men.]]
* OneGenderSchool as well
* [[spoiler:OpeningACanOfClones: While not technically clones per se, the Emul Force recalls the trope since it's used to bring characters "back to life" every time someone dies.]]
* PhlebotinumRebel: Yui, sort of.
* PleasePutSomeClothesOn: In ''Tenshi no Bokura'', Admiral Mariel walks around practically naked. When Shouta asks her to "put something on", [[CompletelyMissingThePoint she dons cat ears but remains otherwise undressed.]]
** Also, [[CantActPervertedTowardALoveInterest Yui to Misato]].
* PoweredByAForsakenChild: the Arume use human and synthetic children as living bomb disposal units.
* TheReveal
* RomanticTwoGirlFriendship: Subverted, since Hagino's interest in Mari goes quite a bit further than that.
* SceneryGorn: In the ''Tenshi no Bokura'' manga, the characters live surrounded by devastated cityscapes, a grim reminder of the recent invasion.
* SceneryPorn
* SchoolgirlLesbians: Older ones too, lots of them.
* SchoolPlay: Which is somehow really important to Hagino.
* SecondEpisodeMorning
* SenselessSacrifice: You'll know it when you see it. Somewhat impressively, it's ''also'' a StupidSacrifice, because the character's death could have easily been avoided without changing the result.
* ShowWithinAShow: Michiko's play is a thinly-veiled parallel to the main story [[spoiler:starring Hagino as Jeanne d'Arc.]]
* SituationalSexuality: Many of the humans engage in homosexuality in the gender segregated areas.
* SlapSlapKiss
* SleepCute
* SpaceWhale: The Blue looks like a mechanical whale.
* StrangeSalute: In ''Tenshi no Bokura'', Admiral Mariel insists on being saluted in a rather idiosyncratic way.
* ThereIsOnlyOneBed: In ''Maiorita Tenshi'' with Sachi and Ai. [[spoiler:Though this turns out to be [[RelationshipUpgrade a reason to be happy.]]]]
* TheMirrorShowsYourTrueSelf: When Nagino is tele-talking with Mari, she's invisible, but Sugawara sees her as a reflection in the water.
* TheTease: Hagino toward Mari--eventually. And then of course there's the abundance of teases in the mangas.
* TheGuardsMustBeCrazy: Azanael is detained after an attack, but she manages to keep a secret control device for her fighter craft, which is repaired by the ships captain.
* TragicHero: [[spoiler:Hagino/Ekaril]]
* UnderwaterKiss
* VichyEarth
* WaveMotionGun
* WhatMeasureIsANonHuman
* WhereAreTheyNowEpilogue
* WholesomeCrossdresser: Shouta and Shinichi in ''Tenshi no Bokura''.
* WillTheyOrWontThey: Hagino & Mari. In the end [[spoiler:they do, but it doesn't last long.]]
* YaoiGuys: Quite a few appear in ''Tenshi No Bokura'', Shinichi being the most prominent.
* YourDaysAreNumbered: [[spoiler:The humans used to clean up Thought Arresting Weapons]]
* YouShallNotPass: [[spoiler:Azanael and then Ekaril at the end of the anime.]]
* YuriGenre
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