* AccidentalInnuendo: One particular item in BBL is referred to as a Bright and Massive Thing. Among others, this leads to the line, "You're up, Massive Thing!"
** It's actually referred to as the Massive Key, designed to open any lock. (Personal theory: it's a [[StealthPun crow]]bar.) Ryouta's the only one to call it a "Massive Thing."
** Also what Ryouta says [[spoiler:after being knocked out]].
-->'''Ryouta''': [[spoiler:"Aargh! Darn it! Why did I let myself get taken from behind like that!?"]]
* ComeForTheXStayForTheY: [[BileFascination Come for the batshit premise]], stay for the shockingly compelling plot and well-written characters.....or how carefully the batshit premise turns out to be crafted.
* CrazyAwesome: Higure Anghel. You wished for the mad love of a fallen angel? [[UpToEleven You got it!]]
** Really, the ''entire game''. Moa took a completely bizarre premise and turned it into ''something amazing''.
* CrowningMusicOfAwesome: Moa has an exceptional ability for choosing tracks for her games that are either emotionally moving or simply fun to listen to.
** [[http://www.youtube.com/watch?v=xo8wCrwLejw Anghel's battle theme]]. One may not even want to finish the battle just to listen to the epic music!
** The heartwrenching [[http://www.youtube.com/watch?v=RrFP7eqM48A music]] that plays at the end of Nageki's route may make the player [[{{Tearjerker}} burst into tears]].
** Everything is better with [[http://www.youtube.com/watch?v=LAWUQHK0u3E "The Dance of The Sugar Plum Fairy"]]. Even Doctor Shuu.
** BBL has a track at a pivotal moment, [[spoiler: [[http://www.youtube.com/watch?v=roNGM9wJOnY Death Tone]]]] which is appropriately both sad and inspirational.
*** ''Holiday Star'' also has a [[http://www.youtube.com/watch?v=EV8H45An3c8 track]] that is inspirational, heartwrenching, and plays at a pivotal moment.
** [[http://www.youtube.com/watch?v=XyjJyNsAIZo These]] [[http://www.youtube.com/watch?v=amveOxTgDww&feature=share&list=PLeTZfVODlyvTRGWVsVFSiBLJ_c4lFXDD9 two]] ethereal songs from ''Holiday Star'' really make the players feel as if they're immersed in an oneiric fantasy world.
** That [[http://judeccan.tumblr.com/post/48822339939 hilariously boss music]] that plays in the first ''Holiday Star'' Chapter and during one of the radio Q and A sessions, when Yuuya's [[BigDamnHeroes being cool]].
* CryForTheDevil: [[spoiler:Doctor Shuu]] appears to rocket-jump over the MoralEventHorizon in the Bad Boys Love route. Then he reveals that he's doing all of this because of [[spoiler:his unrequited love for Ryouta's father and sincere desire to fulfill his dying wish]]. It doesn't excuse the horrific things he's done up to that point, but it does make one feel at least a twinge of pity for him.
* EnsembleDarkhorse: A lot of fan-art is based on Doctor Shuu despite the fact that his romance path is, let us say, not the happiest.
** Nageki runs a close second, with plenty of fanart being drawn of his {{Moe}} human self.
** Anghel is quite popular, presumably because he is both CrazyAwesome and [[{{Bishounen}} extremely pretty]].
** [[CloudCuckoolander And then there's Oko San.]]
* EvilIsSexy: Doctor Shuu. Not quite a DracoInLeatherPants, since a lot of his fans adore him [[http://www.pixiv.net/member_illust.php?mode=medium&illust_id=22726435 while still acknowledging that he is a bit on the murderous side]]. Just a tiny bit, yeah.
* FandomRivalry: With ''VisualNovel/KatawaShoujo'', to an extent.
* FanNickname: "Fat Bird" or "Murderbeaks" for Doctor Shuu.
** "Narcolepsy-sensei" or "Sleepybeaks" for Kazuaki.
** "Simple Bird" for Okosan.
** "Ousama" for [[SpellMyNameWithAThe The King]]. "Ousama" is what he calls himself in Japanese, and it does mean the same thing.
** Anyone who regularly plays this game, especially with friends, develops nickname. Examples: "Sadbird" for Nageki, "Saddest Bird" for [[SpellMyNameWithAThe The King]], "Fab Bird" for Nishikikouji, "Secret Bird" for Anghel, and "Unapologetically Racist Bird" for Sakuya.
* GeniusBonus: Many of these may be apparent to players with hobbies related to birds, such as keeping pet birds or studying ornithology. See the Hatoful Boyfriend [[Fridge/HatofulBoyfriend Fridge Brilliance]] section for a more complete and detailed list of these.
** Upon introducing Shuu, Hiyoko mentions that even just talking to him can bring you down with horrible diseases such as [[http://en.wikipedia.org/wiki/Aspergillus Aspergillus]] or [[http://en.wikipedia.org/wiki/Psittacosis Psittacosis]]. Both of these diseases have certain strains that can affect both birds and humans.
* HarsherInHindsight: Practically everything involving [[spoiler:Fake!Kazuaki[=/=]Hitori]].
* [[spoiler: HeroicSacrifice: Nageki kills himself in an attempt to destroy the Charon virus, so that he can't be used as a weapon against humanity.]]
* HoYay: Mainly in the [[MeaningfulName Bad Boys Love]] route, although it's limited to [[spoiler:Doctor Shuu's unrequited feelings for Ryouta's father]] in a flashback, and ''possibly'' Kazuaki's feelings over [[spoiler: his late foster-brother Nageki]].
** Yuuya's flirtatious nature is by no means limited to girls. He even says, "I'm always straight in love. Well, almost always." When he overhears Ryouta and Sakuya discussing him, he says, "I guess I'm topic of choice among the boys now as well as the girls. Not that I mind."
*** Sakuya is his ''brother''.
** The manga also alludes to this when, after Ryouta tells how Yuuya's locker is usually overflowing with gifted beans on Legumentine's, Sakuya mentions that St. Pigeonation's is (excluding the player's character) an all-boys academy.
** In ''Holiday Star'', [[spoiler:Hitori and the original Kazuaki seem to have been very close, albeit in a horrendously dysfunctional way, with Hitori ultimately taking advantage of Kazuaki's trust to kill him and steal his identity. In the alternate universe shown in the sidestories, both of them are alive and working together at St. Pigeonation's, and Kazuaki is still very attached to and dependent on Hitori, who seems rather less enthused about the whole affair.]]
** LesYay: Hiyoko's admiration of [[CoolBigSis Azami]] borders on full-blown swooning in a couple of scenes with her even thinking, "She's so cool! I think I'm in love...!" after Azami saves her from a gang of punkgeons. Sadly, there's no actual route for her and her side story consists of Hiyoko setting her back up with her former boyfriend.
* ItWasHisSled: The manga tells you right from the start that [[spoiler: Nageki is a ghost]], which was only revealed at the ''very'' end of his route in the game.
* MagnificentBastard: '''Doctor Shuu'''.
* MemeticMutation: It's become a minor RunningGag for some that this is "[[VideoGame/TeamFortress2 The Medic's]] favorite game", because he keeps a flock of doves in his infirmary.
** People love to joke that UsefulNotes/NikolaTesla invented this game or that it would be his favourite because... well... [[http://claudiears.wordpress.com/2011/10/01/nikola-tesla-and-the-pigeon-love-story/ this]] happened.
** Also, Doctor Shuu seems to have quite a following. [[http://www.youtube.com/watch?v=4T_VJNx7WW4 Just read]] [[http://www.youtube.com/watch?v=rba0la5_n3g the comments.]] [[http://www.youtube.com/watch?v=mG1u1Gc9c_g Also, Iwamine-sensei runs Pakistan.]]
** For a while, due to a translation error accidentally saying Dr. Shuu had hands, there was a minor meme in which Shuu would be drawn or Photoshopped as a bird with human arms and hands sticking out of his body.
** In ''Holiday Star'' [[spoiler: The King]] is [[spoiler:original Kazuaki]]'s [[Anime/PuellaMagiMadokaMagica witch form]] after he fell into despair, and [[spoiler: Holiday Star]] is his witch's barrier.
** Still a better dove story than Twilight.
* MST3KMantra: This is how Ryouta explains the congruency between BBL's and ''Holiday Star's'' timelines during ''Holiday Star's'' Radio Session. "Just don't think about it too hard and you'll be fine! In the end, it's because unlike books or movies, visual novels have all kinds of branches and possibilities."
* NarmCharm: The premise is ridiculous, the script is riddled with typos and the occasional formatting error, the graphics are a somewhat jarring mix of bird photos, 3D backgrounds and the occasional hand-drawn or photoshopped image... and somehow, it all still works.
* NightmareFuel: The ''Hatoful Boyfriend'' series contains enough Nightmare Fuel to warrant its own [[NightmareFuel/HatofulBoyfriend page]].
** [[spoiler:The scarecrow-like monster]] in the Bad Boys Love route. You ''will'' jump when you first see it. So much more nightmarish when you learn its origins.
** There's little of [=BBL=] that doesn't fall under this trope, and most of what ''does'' falls under [[TearJerker a much more depressing category.]] The humorous bits that would be perfectly at-home in the normal routes actually come off as being ''completely'' out of place at this point.
** The Game Over screen [[spoiler: when you get killed at your home.]] It looks like something out of ''VideoGame/YumeNikki''.
*** It's actually a reference to ''VideoGame/{{Shadowgate}}''.
** [[spoiler: The King]] in ''Holiday Star''. Big time.
*** The 4th chapter. If you make all the right choices, it's horrifying enough. Make a wrong one at any point? ''Forget about sleeping that night,'' and good luck at ever taking [[spoiler: the phrase "Happily Ever After"]] pleasantly ever again. It even makes [[spoiler: a ''freaking picture book'']] terrifying.
* RescuedFromTheScrappyHeap: Do you find [[RoyalBrat Sakuya]] and [[HandsomeLech Yuuya]] insufferable? You'll most likely change your tune ''big time'' after you've played through the Bad Boys Love route. Yuuya [[HiddenDepths takes it yet further]] in ''Holiday Star''.
* SurpriseCreepy: Again, a game about dating pigeons ''has its own Nightmare Fuel page''.
* WhatDoYouMeanItsNotForKids: The English download site for the full game gives it a G-rating. If you've played this game in its entirety, you'll know just how deeply and hilariously wrong this rating is.
* WhatDoYouMeanItWasntMadeOnDrugs: Well, it ''did'' start out as an April Fool's joke... that being said, Oko San and Anghel's routes (and the characters themselves) are exceedingly bizarre even for ''this'' game.
** Actually, subverted in that, despite the things appearing completely and utterly crazy in the beginning, all this has an explanation.
* TheWoobie: Almost ''every'' main character is turned into this in the Bad Boys Love route, with healthy doses of TheReveal, BreakTheCutie, and TearJerker.
** In ''Holiday Star'' [[spoiler:The King]] becomes this once we learn of his tragic back story. His back story may especially hit close to home for players who have ever suffered from social isolation, [[{{UsefulNotes/Depression}} clinical depression]], and/or [[{{UsefulNotes/Suicide}} suicidal thoughts]].
* WhatAnIdiot: While it seems each of the route's characters are [[HiddenDepths well written and have great characterization]], Hiyako herself makes some questionable choices. For example:
** In [[spoiler: Shuu's route]], near the end where she discovers [[spoiler: he is a murderer killing the students]], [[spoiler: Shuu enters the room with clear intent of killing her]]. He locks he door, fair enough that she can't get out normally. Other than that, she doesn't have any physical restraints on her. So why can't she take [[spoiler:him on? Sure, he has a cleaver but he is a BIRD]]. There really should be a high probability of her [[spoiler: taking him out]], especially as [[ActionGirl a hunter gatherer]]. [[{{Pokemon}} Immobilized by love?]] then what about:
** In [[spoiler: Kazuaki's route]], near end where she stumbles upon [[spoiler: Shuu]] who seems to her suspect of prying into his matter and asks her a favour. At this point, she is aware of his notoriety and a lot of [[LetsPlays LetsPlayers]] tell her to run. However, you are not given the option and are forced to [[spoiler: fall for his obvious trap]]. Luckily, [[spoiler: Kazuaki]] saves you out of it.