History Literature / HumanityHasDeclined

* SweetTooth: ''The fairies.''

* BleachedUnderpants: Prior to writing the light novels, Tanaka Romeo was well known for writing the scenarios for [[HGame H-Games]] of the [[{{Utsuge}} depressing]] PornWithPlot variety. Much of the CringeComedy remains, however.

* AloofDarkHairedGirl: {{Deconstructed|Trope}}. The reason the protagonist was this in school is because it's a psychological defense against a toxic environment. She's deliberately being nasty as a social firewall, which others somehow interpret as charming.

** DuelingProducts: In-Universe example: Y's revival of the Doujin Manga creates unwanted competition for her own publication.

* FirstPersonSmartass: The heroine.
** DeadpanSnarker

** The Secret Factory arc seems to have one.

* ImportantHaircut: {{Inverted}}. It's after experiencing firsthand the potency of Fairy Co. hair growth tonic that the heroine begin to be interested in Fairy Co., thus starting the adventure.

* LargeHam: The Director, [[spoiler:the chickens]], Y, Oyage... Most side characters in general, really.

* LetsMeetTheMeat: The bread-robot guide in the fully-automated factory. He even rips himself apart in his belief that he's not delicious, resulting in red (carrot juice) mess everywhere.
** [[spoiler:The real masters of the factory are the sentient, mobile skinless chickens with a plan to take over the world.]]

* RagnarokProofing: A remarkable amount of pre-decline technology still works.
** This is briefly discussed regarding the Human Monument Project, as they say that digital media tends not to last as long.
* RedOniBlueOni: The heroine, as the latter, and Y, as the former.
** Also, Pion and Oyage. Pion as the stricter, more by-the-book Blue Oni, an Oyage as the renegade Red Oni.

* {{Satire}}:
** Episodes 3 and 4 are both a parody and critique of modern doujinshi and manga business practices, respectively.

* OurFairiesAreDifferent: Tiny, addicted to sweets, evolved from humans, don't act at all bright despite apparently having super-advanced technology, and have permanent vacant grins. No wings, either.

* DysfunctionJunction: [[spoiler:Wild Rose Society.]] When it's revealed, one can't help but think that the author has [[TakeThat a bone to pick]] with [[spoiler:''LightNovel/MariaWatchesOverUs'']].

An anime adaptation by studio Creator/{{AIC}} A.S.T.A. premiered as a part of the Summer2012Anime lineup and was simulcast on [[http://www.crunchyroll.com/humanity-has-declined Crunchyroll]]. It was licensed by Creator/SentaiFilmworks with a home video release in 2013. There are also three separate manga adaptations written by Romeo Tanaka himself.

''Humanity Has Declined'', known in Japanese as ''Jinrui wa Suitai Shimashita'', is an eleven-volume light novel series written by Romeo Tanaka which ran from May 24, 2007 to September 16, 2016. The light novels were illustrated by Tooru Yamasaki from 2007 to 2011, but Yamasaki was later replaced by Sunaho Tobe, who took over the illustrations for the rest of the series.

* {{Cloudcuckoolander}}: An entire Cloudcuckoolander subspecies of humanity exists, with their thoughts making little sense to the audience. [[BaitAndSwitch Then there are the fairies]], who take things {{up to eleven}}.

* AwesomeMcCoolname: One fairy decides to name himself Sir Christopher [=McFarlane=] in episode 10.

* RapunzelHair: The heroine.

''Humanity Has Declined'', known in Japanese as ''Jinrui wa Suitai Shimashita'', is an eleven-volume light novel series written by Romeo Tanaka which ran from May 24, 2007 to September 16, 2016.

* YouGottaHaveBlueHair: Characters are not limited to natural hair colours. Justified for the fairies, not justified for Old Humanity.

[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/jinrui_461.jpg]]
[[caption-width-right:350:[[NoNameGiven The U.N. Mediator and Her Assistant.]]]]

* AloofDarkHairedGirl: {{Deconstructed}}. The reason the protagonist was this in school is because it's a psychological defense against a toxic environment. She's deliberately being nasty as a social firewall, which others somehow interpret as charming.

* VagueAge: The protagonist started secondary school late but skipped grades, getting to [[https://en.wikipedia.org/wiki/Sixth_form sixth form]] quickly.

* WidgetSeries: A defining example.
** ''Especially'' the Homecoming arc. The strangeness wasn't even made by [[AWizardDidIt the fairies]]!

* DysfunctionJunction: [[spoiler:Wild Rose Society.]] When it's revealed, one can't help but think that the author has [[TakeThat a bone to pick]] with [[spoiler:''LightNovel/MariaSamaGaMiteru'']].

* {{Kemonomimi}}: Pion has ''some'' kind of animal ears.

* AGodAmI: Inverted! After being declared a god by the fairy, the protagonist starts to feel uneasy, and quickly passes the baton to someone else.

* ConspicuousCG: The secret hall in the Tea Party arc.