Portmanteau Series Nickname

Many Anime series have fairly lengthy titles. Frequently, they wind up picking up a Portmanteau Series Nickname, with a syllable or two of each word in the series name. Sometimes, the producers explicitly encourage this, and refer to the series using the nickname in the Post Episode Trailer.

Portmanteau words are the Japanese equivalent of acronyms. The Japanese language is syllabic -- instead of single letters, Japanese is built from entire syllables; consonants (except "n") don't occur by themselves. So where a Western term would produce an acronym, the Japanese equivalent produces a pronounceable word. The Japanese use portmanteau terms in much the same way that English speakers use acronyms. Which is to say, frequently. More so recently thanks to the need to create short hashtags on Twitter, some of which have been officially endorsed by the author or publisher.

Probably the most famous is Pocket Monsters becoming Pokémon. The longer name is official for both the games and the show in Japan, but couldn't be used in America because an early-90s toyline/comic/cartoon had secured the trademark on the name "Monster In My Pocket". This is actually slightly common; some of these are so ubiquitous that they get used as the official English titles.

See also Officially Shortened Title

Alphabetical order by official Japanese title, please.

Anime and Manga

 * Aishiteruze Baby -> "AiBaby"
 * Ai Yori Aoshi -> "Ai-Ao" (the creator uses this himself in the omakes)
 * Animal Yokocho -> "AniYoko"
 * Ano Hi Mita Hana no Namae o Bokutachi wa Mada Shiranai -> "Ano Hana". It's a necessity
 * Arata Kangatari -> "Arakan"
 * Azumanga Daioh -> "AzuDai"
 * Baka to Test To Shoukanjuu -> "Baka Test"
 * Bakuretsu Tenshi ("Burst Angel") -> "Bakuten"
 * Bamboo Blade -> "Banbure"
 * Berusaiyu no Bara (Rose of Versailles) -> "Berubara"
 * Black Lagoon -> "Burakura"
 * Bobobo Bobobobo -> "Bo7"
 * Death Note -> "Desuno"
 * Densetsu no Yuusha no Densetsu-> "Den Yuu Den"
 * D.Gray-man -> "D.Gure"
 * Eureka Seven -> "E7"
 * Fruits Basket -> "Furuba"
 * Fushigi Yuugi -> "FY", and more rarely, "FushiYuu"
 * Futari wa Pretty Cure (and such) -> "Precure"
 * It's also a pun (try pronouncing "Precure" in an Engrish accent) on purikura (lit., "Print Club"), those trendy photobooths popular in Japan. Just why is a mystery; its relevance is never alluded to within the series.
 * Gendai Shikaku Bunka Kenkyuukai -> Genshiken (A special case; the official title is Genshiken; the long form is used only in-series for the actual club.)
 * Ginga Eiyū Densetsu (Legend of the Galactic Heroes) -> GinEiDen
 * Gokudo no Sensei -> Gokusen
 * Gravitation -> Gravi
 * Hachimitsu to Kurobaa ("Honey and Clover") -> "Hachikuro"
 * .hack//tasogare no udewa densetsu -> "Udeden"
 * Hagane no Renkinjutsushi (Fullmetal Alchemist) -> "HagaRen"-> FMA
 * Hanazakari no Kimi-tachi e -> "Hana Kimi"
 * Hanbun no Tsuki ga Noboru Sora -> "Hantsuki"
 * Hidamari Sketch -> "HidaSketch"
 * Hikaru no Go -> "HikaGo"
 * Hime Chen Otogi Chikku Idol Lilpri -> "LilPri", short for the characters' group name "Little Princesses."
 * Ichigo Mashimaro ("Strawberry Marshmallow") -> "IchiMashi"
 * Kamichama Karin -> "KamiKarin"
 * Some fans also try to shorten the sequel's title (Kamichama Karin Chu) to "KamiChu", unaware that's it's already the name of another series (or more accurately, the Portmanteau Series Nickname of another series).
 * Kamichu -> already a portmanteau of "Kamisama de Chuugakusei" (Middle-school student god)
 * Kami Nomi Zo Shiru Sekai ("The World God Only Knows") -> "Kaminomi"
 * Kanojo ha kawaii "kon" to suru ("she gives a cute "kon" yelp") -> Kanokon, which, similarly to Genshiken is actually the only title ever used, but refers to the title of the first chapter.
 * Kareshi Kanojo no Jijyou ("His and Her Circumstances") -> "Kare Kano"
 * Kaze to Ki no Uta -> KazeKi
 * Kimi Ni Todoke -> "KimiTodo"
 * Kirby Right Back At Ya -> "KRBAY"
 * Kochira Katsushikaku Kameari Koen Mae Hashutsujo -> "Kochikame"
 * Kodomo no Jikan -> "Kojika"
 * Kodomo no Omocha ("Child's Toy") -> "Kodocha"
 * Kono Minikuku mo Utsukushii Sekai (This Ugly Yet Beautiful World) -> "KonoMini"
 * Kore wa Zombie Desu Ka -> "Korezon"
 * Kotonoha no Miko to Kotodama no Majyo to (The Mikos Words and The Witches Incantations) -> "MikoMajyo"
 * Kujibiki Unbalance (from Genshiken) -> "Kujiun". (Another special case as the name "Kujiun" was introduced in-series in the first ep of Genshiken.)
 * Kyoto Animation (the studio) -> Kyo Ani (and also "KeyAni" for adapting so many Key games)
 * Kyou Kara Maou -> "MaruMa" (Actually not technically portmanteau as it was named after the symbol - the character 'ma' from 'maou' in a circle 'maru'.)
 * Ladies Versus Butlers -> "LadiBato"
 * Lovely Complex -> "Love* Com"
 * Maria-sama ga Miteru ("The Virgin Mary is Watching") -> "Marimite"
 * Matantei Loki Ragnarok -> "MaLoki"
 * Mermaid Melody Pichi Pichi Pitch -> "P3"
 * Mukuro Naru Hoshi - Tama Taru Ko (Shadow Star) -> Naru Taru
 * Okusama wa Joshikousei (My Wife Is a High School Girl) -> "OkuKousei"
 * Oniichan no Koto Nanka Zenzen Suki Ja Nai N Dakara Ne -> "OniiKoto"
 * Ore no Imouto ga Konna Ni Kawaii Wake ga Nai -> "Ore Imo"
 * Ookiku Furikabutte ("Big Windup!") -> "Oofuri"
 * Otome wa Boku Ni Koishiteru -> "Otoboku"
 * Panty and Stocking With Garterbelt -> "Pansuto"
 * Paradise Kiss -> ParaKiss
 * Pita-Ten - special case, as the official title is already a shortening of Pitari Tenshi (clinging angel)
 * Pocket Monsters Special -> Pokémon Special -> "PokeSpe"/"Pokesupe"
 * Princess Princess -> "PuriPuri" (Unfortunately the actual name of a very different manga series.)
 * Puella Magi Madoka Magica: -> "MadoMagi"
 * Renkin San Kyuu Magical Pokaan -> "MagiPoka"
 * Romeo X Juliet -> "RomeJuli"
 * Rosario+Vampire -> "Rosa-Vam" (which is also used by the author)
 * Rurouni Kenshin -> "Ruroken"
 * Saishuu Heiki Kanojo -> "Saikano"
 * Saiunkoku Monogatari -> "SaiMono" and "KokoMono"
 * Samurai Seven -> "Sam7"
 * School Rumble -> "SukuRan"
 * Scrapped Princess -> "Sutepri" (shortened to "Scra-Prin" in English)
 * An interesting case; it's something of a back-translation on the Japanese side. The original title had the English "Scrapped" [Sukurappudo] rather than the Japanese equivalent "Suterareta."
 * Shaman King -> "ManKin"
 * Shinshi Doumei Cross (Gentlemen's Alliance Cross) -> "ShinKuro"
 * Sister Princess -> "SisPri"
 * Soredemo Machi wa Mawatteiru -> "SoreMachi"
 * Soukou no Strain -> "S-Strain"
 * Star Driver -> "Sutadora"
 * Strawberry Panic -> "SutoPani" (just StoPani on English boards)
 * Sugar Sugar Rune -> "S2R" or "Sugar2 Rune"
 * In the anime, "S2R" is engraved on Chocolat's heart holder.
 * Suki na Mono wa Suki Dakara Shouganai!! -> ''Sukisho (or Sukisyo)
 * Suzumiya Haruhi No Yuutsu -> "Suzuharu"
 * Tiger and Bunny -> "TaiBani"
 * Tennis no Ojisama (Prince of Tennis) -> TeniPuri or PoT
 * Toki wo Kakeru Shoujo -> TokiKake
 * Triangle Heart -> "ToraHa" or "Toraha"
 * Trinity Blood -> "Toribla"
 * Ultra Maniac -> "UruMani"
 * Uragiri wa Boku no Namae wo Shitteiru -> "Uraboku"
 * Uta no Prince Sama -> "UtaPri"
 * Wangan Midnight Maximum Tune -> "WanganMaxi"
 * Watashi ga Motenai no wa Dou Kangaete Mo Omaera ga Warui -> "WataMote"
 * Yami no Matsuei -> "YamiMatsu"
 * Yami to Boushi To Hon no Tabibito -> "Yamibou"
 * Yumeiro Patissiere: "YumePati"
 * Yu Yu Hakusho -> "YuuHaku," "YuYu"

Card Games

 * Pokémon Card Ni Natta Wake -> Pokewake.

Literature

 * Kara no Kyoukai -> "Rakkyo"

Professional Wrestling

 * All Japan Womens Pro Wrestling (Zen Nihon Joshi Puroresu) -> "Zenjo"

Theatre

 * Bishoujo Senshi Sailor Moon Musicals -> "SeraMyu" ("Sera" is shortened Japanese rendition of "Sailor (Moon)" and "Myu" is the same from "musical")

Video Games

 * Banjo to Kazooie no Daibouken -> "BanKaz"
 * Beatmania -> "Bemani" (no longer used for this purpose; in recent years, "Bemani" is used to refer to Konami's Rhythm Games as a whole.)
 * Bokujo Monogatari  -> "Bokumono"
 * Bokura no Taiyou -> "Boktai"
 * Crash Bandicoot -> "KuraBan"
 * Double Dragon -> "DabuDora" (also applies to Billy and Jimmy's expies, Ryuichi and Ryuji, from the Kunio-kun series)
 * Dragon Quest -> "DraQue" (incidentally, the name "Duracuets" in La-Mulana is an alternate spelling of "DraQue 2")
 * Dragon Slayer -> "Drasle", though this only really shows up in the Japanese title of Legacy of the Wizard, which is Dragon Slayer IV: Drasle Family.
 * Famicom Tantei Club -> "FamiTan"
 * Gensou Suikoden -> "GenSui" (Though Konami simply uses "Gensou" as the abbreviation for the game series.)
 * Guitar Freaks and Drum Mania (collectively) -> "GitaDora"
 * Gyakuten Saiban -> "Gyakusai"
 * Harukanaru Toki no Naka De -> "HaruToki" (Although the "official" short version used in Japanese media is "Haruka" -- it even made its way into the title of the English-language release of the manga adaptation.)
 * By extension, the TV series based on the franchise, Harukanaru Toki no Naka de - Hachiyou Shou -> "HaruHachi" (or, going from the Japanese version, "Haruka8")
 * Inazuma Eleven -> "InaIre"
 * Kimi ga Nozomu Eien ("The Eternity You Wish For", aka "Rumbling Hearts") -> "Kiminozo"
 * Magical Girl Lyrical Nanoha As Portable -> "NanoPo"
 * Metal Gear Solid -> "MeSo"
 * Western example: In fandoms for games which feature the Chinese Civil War (such as Hearts of Iron or Steel Panthers), it's not unusual to sometimes see NatChi and ComChi used for the Nationalist / Kuomintang and Communist forces, at least when they aren't using the KMT and CCP acronyms.
 * Panel De Pon -> "Panepon", which shows up in the Japanese titles of Tetris Attack (Yoshi no Panepon) and Pokemon Puzzle Challenge (Pokemon de Panepon).
 * Pocket Monsters -> Pokemon/Pokémon (the official international name)
 * pop'n music -> "PoMu"
 * Princess Maker -> "PuriMe"
 * Pro Yakyuu Family Stadium -> "FamiSta"
 * Sengoku Basara -> "SenBasa"
 * Shin Megami Tensei -> "MegaTen"
 * One of its more obscure spinoffs, Giten Megami Tensei, is commonly abbreviated as "GigaTen".
 * Sono Hanabira Ni Kuchizuke Wo -> Sonohana
 * Street Fighter II -> "Suto Tsuu" (or "St. II", as one beta for the Genesis port spells it out.)
 * Subarashiki Kono Sekai (The World Ends With You) -> "SubaSeka"
 * Super Mario Bros -> "SuuMari"
 * Super Smash Bros -> "SmaBro" (mostly in Japan), "SSB(M,B)"
 * The "Smash" ability from Kirby & the Amazing Mirror is "SumaBura" when romanized from the Japanese name.
 * Tokimeki Memorial -> "TokiMemo"
 * Yoake mae yori ruriiro na ~Crescent Love~ -> "YoakeNa"
 * Zeruda no Densetsu -> "ZerunoDen"

Other

 * Drinks chain Beverages & More! now calls themselves BevMo! (Yes, with the exclamation point in both versions.)
 * Despite its common use, "Famicom" is technically a nickname for the Family Computer (the Japanese version of the Nintendo Entertainment System). Nintendo made the abbreviation official for the Super Famicom, which didn't stop Bandai from abbreviating that name further with their SuFami Turbo accessory.
 * American shipping company Federal Express rebranded to FedEx, a popular nickname, and used both till 2000.
 * National Biscuit Company -> Nabisco, they changed their name so long ago, most people don't even know of the full name.
 * The British bank National Westminster Bank rebranded to NatWest in the mid 90s.
 * As did now-defunct American bank Washington Mutual ("WaMu").
 * Service Games was originally founded as an American company, but after it opened its Japanese offices in the early 1950's, they would eventually be referred to as Sega.
 * Japan Capsule Computer Co. was only in the business of making video game arcade cabinets, which they thoughtfully named "Capsule Computers." Now that they're in the business of making games themselves, we have since known them as Capcom.
 * This was then inverted with their first would-be Mascot, Captain Commando.
 * Jagex's name originally stood for "Java Gaming Experts", though they have redefined it as "Just About the Game Experience".
 * Bluesman Keb' Mo', originally Kevin Moore (not that one).
 * JLo.