When Ordinary High-School Student Kazuto Hongo chases after a thief, who steals and breaks an ancient mirror at his school campus, he's transported back to ancient China. Are we good so far? Now, take the Romance of the Three Kingdoms story and Gender Flip nearly all male characters from the original epic into action girls of varying degrees of affection for Kazuto, and you get the perfect harem Visual Novel called Koihime†Musou, developed by BaseSon. All principal heroines in the game are expies of the (male) generals from the original epic and the former's names are derived from the latter's by reading the original Chinese characters in their names as kanji. Additionally, all of them have a true, "private" name usually reserved for close friends, and several sport a courtesy name. European eroge publisher MangaGamer acquired the localization rights and released an English version on February 28, 2011.
A remake of the visual novel Shin Koihime†Musou was released with more characters added in from Romance of the Three Kingdoms and following suit by genderflipping them. Not only does it pay more attention to the original epic but it also allows players to choose which faction to ally with, rather than the preset one in the original game.
The series has since developped into several entries and spin-offs listed below.
Here is a chronological list of all the games in the series.
- Koihime†Musou (2007 in Japan, 2011 worldwide): A mostly original story based on the Romance of the Three Kingdoms, featuring the major generals of the period. Albeit presenting itself as an adaptation of the Three Kingdoms, it quickly takes its own route to become more of a standard Unwanted Harem story with few references to the original epic. Ordinary High-School Student Kazuto Hongou ends up in the Three Kingdom period after attempting to stop a thief, and circumstances led him to become the leader of the temptative Shoku Kingdom, alongside the famed warriors Kan'u and Chouuhi, taking the identity of Ryuubi in all but name. Because of its status as an original story, it has several instances of Early-Installment Weirdness and bordering on Porn Without Plot.
- Shin Koihime†Musou (2008): A broad retelling of the first game and more closer to the original epic. In this version, the prologue in the present time and the thieving is removed altogether to have Kazuto simply being transported to another world in his sleep. This time, the player is given the choice to join one of the titular three Kingdoms of Shoku, Gi, and Go. Several new characters fill in their ranks, most notably Ryuubi as the leader of the Shoku Kingdom, and Sonsaku as the leader of the Go Kingdom who replaces her sister. Almost none of the first Koihime plot remains, aside from a couple of side characters who appear in an additional story unlocked after clearing the three routes.
- Shin Koihime†Musou ~Moeshouden~ (2010): The third and final installment of the original series, which the battle sequences found in prior games for the purpose of focusing entirely on the Unwanted Harem aspect.
- Shin Koihime†Musou -Kakumei- (2017-2019): Three remakes of Shin Koihime†Musou, each centering on one of the titular kingdoms while adding characters from Eiyuutan and more historical battles.
- Souten no Haou (2017): Centered on Gi and Sousou's ambition to unite China by force.
- Son Go no Ketsumyaku (2018): Centered on Go and the Son family of warriors in their struggle to preserve their legacy among the warring kingdoms.
- Ryuuki no Taimou (2019): Centered on Shoku and Ryuubi's attempts to unite China with peace and diplomacy.
- Shin†Koihime Eiyuutan 1-2-3 (2015-2016): A collection of short and humorous stories set in various timelines in the aftermath of Shin Koihime†Musou, with updated art and new artists. It also features another bunch of new characters from the original epic for the three Kingdoms and the Imperial Kan Court.
- Shin†Koihime Eiyuutan 4-5-Gaiden (2022-2023): A second collection of short stories for Go, Gi, and the Imperial Kan Court.
- 4 notably features a short prequel involving a young Sonken Bundai in her bid to create a new kingdom from scratch, alongside the younger incarnations of the three oldest generals of Go.
- Gaiden - Hakugetsu no Tomoshibi makes a new spin on the usual formula: Kazuto ends up in the care of the Kan Imperial Court, instead of the three kingdoms. As China prepare to fall into full-blown civil war, Chancellor of State Toutaku wants him to use his knowledge of the future to prevent such a fate, against all of the other warlords keen on taking down the Imperial Court.
- Otome Taisen Sangokushi Engi (2011): A fighting game for arcade machines and PC. It was adapted for PlayStations 3 and 4 on January, 2016 under the new title Koihime Enbu. Degica games has released this adaptation for overseas PCs via Steam, alongside a third version, RyoRaiRai, in 2018.
- Web Koihime†Musou: Battle Maidens (2012): A web-based strategy game, free to play with microtransactions. It's been jokingly said that it is like Evony, except that it actually has girls. Plans to release the game overseas crashed abruptly when Beanfun, the distributor, had its Europe and US branches closed by Gamania, its parent company.
- Sengoku†Koihime (2013): A Spiritual Successor set during the Sengoku period. It stars Kazuto's nephew many years after the original, except his uncle specifically trained him to prepare for his arrival in the Sengoku period, leading to a much stronger, much smarter protagonist.
- Suzukuri Dungeon: Karin in the Mountain (2019): A Simulation Game and dungeon management game which features characters of the Koihime series in an entirely different genre and setting.
- Koihime†Musou (2008-2010): The Animated Adaptation of the same name, set in its own continuity and doesn't adapt the Visual Novel, adding instead several original characters from the original epic whose versions differ greatly from the later installments. Most notably, the adaptation remove Kazuto altogether in favor of having Ryuubi as its main character. Later seasons were released as Shin†Koihime Musou and Otome Tairan respectively.
For individual character tropes, see the full character list.
Tropes in relation to multiple characters or the franchise:
- Accent Adaptation: Blood Knight Chouryou in the Japanese version had a Kansai dialect. The MangaGamer translator went on the record saying "[he] didn't really bother with making her speech 'accented' this time around, instead focusing more on the personality she conveyed through it."
- Action Girl: Pretty much any girl that wields a weapon, even some that don't, such as Chinkyuu punishing a stranger for getting too close to Ryofu.
- Age Lift: Some of the cast of characters are a different age than their original counterparts.
- The Alcoholic: Gengan's portrayed as one in Otome Tairan; the locals claim she's seldom seen sober.
- Chouryou may be the other; anyone who can gulp down wine like there's no tomorrow probably has to be one.
- Alternate Universe: According to Chousen in the first game, Kazuto didn't travel back in time, but rather entered an alternate world, whereas his home is an "original" alternate history from which that alternative history sprang. Moreover, Chousen mentions the existence of more than one alternate reality, each with different possible scenarios happening, including the scenario of the original Romance of the Three Kingdoms. Potentially, this implies that every storyline in the entire franchise (i.e. the Visual Novels, the Animated Adaptations, the OVAs, manga and the Omakes) are all canon.
- He also mentioned a real "true world" (real life) where all the concepts serve as a base for all the "alternate worlds" and that someone in the "true world" might be watching Kazuto, he also mention the creation of other "alternate worlds" based on that world. It's the player, and the new worlds are either the new game pluses or the sequel. In short, every time someone comes up with a fictional idea, they create another universe, an "alternate history", following the script of that person's thoughts. And every time someone thinks up another idea from someone else's story, another alternate history branches off from the first alternate history.
- Amazon Brigade: The Five Tiger Generals, but by Shin Koihime, all factions have their little own brigade, even if they're not named.
- Anachronism Stew: Female military and political leaders, modern underwear, maid cafes. This isn't a particularly realistic depiction of ancient China.
- Animal Stereotypes: Bachou's a horse, Chouhi is compared to either a tiger or a pig, and Chouun to a butterfly.
- Anti-Frustration Feature: Losing a battle gives you the option to redeploy your troops. This gives you reinforcements to your original troop count.
- Babies Ever After:
- The ending of the Go (Wu) faction in the Shin Koihime game, where all the girls (except Sonshoukou, who's too young, and Sonsaku and Shuuyu, who're dead) become mothers to a daughter each, with Kazuto as the common father.
- Also, Kan'u and Ryuubi in the Shu ending of the PSP game.
- Breaking the Fourth Wall: Chousen of all people explains in the late game to the game protagonists that the universe they are in is an alternate universe created by the "true" universe i.e. OUR universe. He even gives a callout of the game's basic premise, calling out the game devs' thought process of "what if we make a story where all the generals from ROTK were gender bent into girls?" and the kicker? Chousen even acknowledges that the events happening around Kazuto are being observed even as he's explaining all of this by another entity...YOU, THE PLAYER.
- Cast Herd: A huge number of characters and most belong to a particular faction.
- Cat Girl: Moukaku and the Nanman girls making up her royal household run around in barbarian-style cat outfits. They also end every sentence with "nya".
- Cherry Blossoms: Where Ryuubi, Kan'u and Chouhi make their pact, a la the novel.
- Chick Magnet: Kazuto managed to somehow attract almost every girl.
- Command Roster: Each of the factions has a few characters that fill a specific set of roles within their respective governments.
- Leaders: Self-explanatory, these are Kazuto (or Ryuubi), Sousou, and Sonken (or Sonsaku)
- General of the Armies: Neither as strong as the Champion nor as cunning as the Strategist, they tend to handle the day-to-day running of the military and counterbalance both by providing decisive action as well as reining in the more violent tendencies of the warrior generals. Shoku has Kan'u, Gi has Kakouen and Go has Shuuyu.
- Strategists: Although each faction has many tacticians, one of them will generally be responsible for grand strategy and the big picture. They will typically give advice on how to handle upcoming battles. Shokatsuryou (later Houtou) serves this role for Shoku, Jun'iku for Gi, and Shuuyu (later Ryomou) for Go.
- Champions: Always outspoken and do not seem to be unit leaders so much as members of their units. They prefer to lead by example rather than by actually leading and, more often than not, are better pointed in the direction of the enemy and turned loose. In Shin Koihime they will generally have powerful offensive supers but few formations. This could really describe a lot of characters, but the most prominent are Chouhi in Shoku, Kakouton in Gi, and Kannei in Go.
- Eyepatch of Power: Kakoton gets one (and a snack) after getting shot in the eye by an archer.
- Genius Bruiser: Several of the characters have shades of this such as Kan'u, Chouun and Kouchuu. All of them are pretty formidable fighters but Kan'u is essentially her kingdom's Minister of War and runs their military apparatus, Chouun unofficially handles Military Intelligence and covert warfare while Kouchuu is a brilliant civil administrator who pretty much runs the day to day affairs of the provinces under their control freeing Koumei to work on infrastructure improvements and "big picture" projects. In the anime Ryoumou in particular has trained as both a Son Family elite bodyguard and as an apprentice strategist, marrying both Brains and Brawn in one character.
- Historical Gender Flip: There are downsides, like Chousen and Himiko being turned into Hard Gay; however, the true aversions are Kada Genka, Saji, Ukitsu and Sonshoukou.
- I Call It "Vera": Kanu's Seiryuengetsutou (Green Dragon Crescent Blade), Ryofu's Houtenkageki (Heaven Piercer) and Chouhi's Viper Spear among others.
- Idol Singer: Choukaku, Chouhou, and Chouryou from Shin Koihime (AKA the leaders of the Yellow Turban Rebellion), complete with makeshift microphones, though we don't actually get to hear them singing during their "live performances" in the game.
- I'm a Humanitarian: In one of Enshou's side-stories in the original visual novel, she gets caught by commoners after the collapse of her country and is nearly cooked and fed to Kazuto. She is only saved by Koumei. This is a reference to the Romance of the Three Kingdoms, which the visual novel is based off of. Specifically, Liu Bei is fed the wife of a commoner. More than that, Kazuto explicitly references this, probably having remembered it from the novels. However, the commoners would never feed their wives to him. Which is where Enshou comes in...
- The Law of Conservation of Detail: You have to be colorblind not to be able to tell who is or will be important.
- Lucky Charms Title: Actually, the game's title is "Koihime†Musou"
- Luminescent Blush: Prevelent with all the girls, though Kan'u makes the best use of this trope.
- Massively Multiplayer Crossover: The franchise appeared alongside three other Eroge series in Twinkle Queen, a Fighting Game that was released for the Nintendo Wii in August 2010
- Meido: Meido cafes in Ancient China = win.
- Metafiction: According to Chousen, the world of Koihime Musou exists because someone wrote the story of Koihime Musou by looking at the Romance of the Three Kingdoms and wondering what it would be like if Sousou and her generals were all lovers and Sonken and Shuuyu were actually enemies. The bit about the genderflipping goes unstated, but the implication is there.
- Indeed, this happens for every story anyone's ever thought up. Entire universes spring into existence from the True History (real life) whenever someone creates a story—and stories based on that stories create more alternative histories that branch out from the first alternative history.
- Motifs: The three factions use several common motifs to distinguish themselves, including:
- Animal Motifs: Some of the Shoku generals use prominent animals from eastern mythology like dragons, tigers, and phoenixes.
- Chess Motifs: The factions respective strategists are often shown playing Xiangqi, the Chinese version of chess. One's skill at Xiangqi is used to demonstrate intelligence and level of strategic ability.
- Color-Coded Armies: Shoku tends to be jade and white, with gold and other colors mixed in depending on the individual personality of the character. Gi is mostly purple and black, although they recruit a lot of vagabonds and mercenaries who wear different clothing. Go is varying shades of red and pink.
- Metallic Motifs: Enshou and her retainers are shown wearing gold or gold-plated armor, to signify both her delusions and the great wealth of her territory.
- Symbol Motif Clothing: Gi armor incorporates a lot of Fashionable Asymmetry while Go characters tend to favor dresses and clothing with a lot of flowy bits.
- Muscles Are Meaningless: Very few characters are drawn with a muscular physique but some of the more diminutive characters are among the physically strongest such as Chouhi or Kyocho. The exceptions are Himiko and Chousen although for other reasons.
- Navel-Deep Neckline: Apparently a trademark fashion of the Wu faction, although sometimes it's just Cleavage Window and/or Navel Window.
- "Not So Different" Remark: Kakouton quick to point out Kougai's refusal to ally with Shoku who caused her imprisonment, only to have Soujin of all people reminding her of her own aggressiveness.Kakouton: "Do you mean that she was punished for her own impulsiveness?"Soujin: "She's kind of like Shun-nee."Kakouton: "Ugh..."
- One-Steve Limit: Shin Koihime game introduces Idol Singer Chouryou, not to be confused with the Blood Knight Chouryou
- Only One Name: Simultaneously played straight and subverted: all characters have their family names mashed together with their given ones, but each has at least two more given ones
- This is out of a Translation Convention for all RoTK adaptations in Japan; where the full name of the character is considered as a family name for all facts and purposes, and the "given name" would be assigned to the courtesy name.
- Self-Censored Release: The first game originated as a Windows eroge, which had the sex scenes removed starting with the PS2 port.
- Tactical Rock–Paper–Scissors: Battles in the visual novels: archers beat spearmen, spearmen beat cavalry, cavalry beat archers.
- Too Long; Didn't Dub: Because all translations insist on using the direct Japanese equivalents of the characters' actual Chinese names, most of the international audience don't even know it's based on Romance of the Three Kingdoms, and those who do have an incredibly hard time following along trying to keep track of who everyone's supposed to be.
- Tsundere: There's at least one in every faction in the visual novel, but Bachou, Sousou and Sonken stand out the most.
- Under Boobs: Ukin in her battle outfit in the visual novel, and in some angles of the anime. Naturally, Chouryou, since she wears a sarashi.
- Updated Re-release: The PS2 version of the first game has endings for Chouun, Bachou and Kouchuu
- Verbal Tic:
- Chouhi's "Nano da!" and Ukin's "-nano", although she ends some sentences with just "-no"
- The Nanban Barbarians' "Nyaa!"
- Waif-Fu: Almost all girls in response to going up against mooks, most notably Chouhi, Kyocho and Ten'i.
- We Have Reserves: The vast majority of Enshou's 'strategies' are to charge forward and incur massive casualties. To be fair, this isn't really because she's cruel or villainous, she's just an idiot who thinks she's an incredible commander.
- Weapon-Based Characterization: Rather than the standard tropes, the Shu faction tends to favor polearms, the Wu faction largely use swords and the Wei faction bucks this trend by each having their own weapon. Anyone using an oversized regular weapon or toy is probably a comic relief character.
- World of Action Girls: Because the characters are Historical Gender Flips of the figures in a Chinese novel about war, the warlords and soldiers are all women.