IOSYS

IOSYS is a prolific Doujinshi circle that specializes in music remixes, particularly vocal remixes of the background music from the Touhou Project series, with 32 albums (as well as several karaoke/alternate remix albums, one best-of album, and one re-release) just dealing with Touhou in the past five years. Many of their vocal remixes have been given music videos by various artists.

IOSYS's (Touhou) albums to date:
 * Touhou Kazakuraen ~ Phantasmagoria mystical expectation (May 2006)
 * Touhou Otomebayashi (August 2006): Features IOSYS's biggest (and perhaps most memetic) song "Marisa Stole the Precious Thing"
 * Touhou Tsukitourou (December 2006): Features IOSYS's second biggest song "It Stops at the Affected Area and Immediately Dissolves ~ Lunatic Udongein" (a.k.a. "Overdrive")
 * Touhou Eijanhou (May 2007): Remixes of the stage and boss themes from Imperishable Night (except the Extra Stage, for some reason)
 * Touhou Suisuisuusuu (August 2007)
 * Touhou Kasokusouchi (December 2007)
 * Touhou Makashinsai (May 2008)
 * Touhou Souyuu Shinpi (August 2008)
 * Touhou Hyousetsu Kashuu (November 2008): Remixes of fan-favorite Cirno's Leitmotif (and, appropriately, their 9th album)
 * Touhou Bubbling Underground (December 2008)
 * Touhou Chotto Matten (March 2009)
 * Bloom (March 2009): Solo instrumental remixes by IOSYS's guitarist, ARM
 * Touhou Nengara Nenjuu (August 2009)
 * Touhou JeuXinTerdiTs (December 2009): Like Bloom, but with IOSYS member minami taking the spotlight
 * Touhou Ageha (February 2010)
 * Touhou Crystallized Ocean (March 2010)
 * Moero! Touhou Brass Band (May 2010): Remixes of boss themes done in the style of high school baseball songs
 * Touhou Faithful Star (July 2010): The follow-up to JeuXinTerdiTs
 * Touhou Koiichigo Musume+ (August 2010)
 * Touhou Merry-Go-Round (September 2010): Remixes of themes from Embodiment of Scarlet Devil done in the style of, well, merry-go-round music
 * Touhou Fushigi Kakumei (October 2010)
 * Touhou Unfufuufu (December 2010)
 * Touhou Meringue Shoujo Yakou (March 2011)
 * Touhou Variable Spellcaster (May 2011): The follow-up to Faithful Star (i.e., yet another solo minami work)
 * Touhou Ageha Destiny (July 2011): Despite its name, not a re-release of Touhou Ageha
 * Touhou Precious Ryuusei Shoujo (August 2011)
 * Touhou Reflection of a Drive (September 2011): The follow-up to Variable Spellcaster (yes, more minami)
 * Touhou Telepathy Shoujo Kashuu (October 2011): Remixes of Satori Komeiji's theme (like Hyousetsu Kashuu, but with no drama tracks)
 * Touhou Electric Denpa Shoujo (December 2011)
 * Quality Underground (April 2012)
 * Touhou Twilight Heaven (April 2012)
 * Touhou Ageha Nightmare (May 2012)

IOSYS is also known for the song "FOE", a remix based around the infamous bosses in mook clothing from Etrian Odyssey. They provided one of the endings for the anime Penguin Musume Heart, and many of the songs for Yumekui Merry.

See also Albatrosicks, a side project created by members ARM, quim, and miko to do their own stuff, and Sugar Honey Babies, IOSYS' "original idol unit".

Tropes that appear in IOSYS's work:

 * Alternate Character Interpretation: IOSYS, being deeply ingrained in Touhou fandom, tends to take many of the same liberties with characterization as the print side. In particular, they are virtually the Trope Codifier for the "Tsundere Alice" characterization, thanks to remixes such as "Marisa Stole the Precious Thing", "Alice --> Sweet", and "Doll's Play".
 * Audio Adaptation: Touhou Hyousetsu Kashuu, Touhou Bubbling Underground, and Touhou Chotto Matten each contain three or four drama tracks that either tell a continuing story (in the case of Touhou Hyousetsu Kashuu) or shorter, independent ones.
 * Clumsy Copyright Censorship: Averted, for the most part. IOSYS re-released its Touhou Tsukitourou album from 2006 as Touhou Tsukitourou Safe! in 2009. The album had three new tracks, drawn from other IOSYS sources (including a previously limited-issue track), while removing three others. The three removed? Parodies of songs from Saint Seiya, Japanese singer Yousui Inoue, and Haruhi Suzumiya (the below-mentioned "Kire Kire Mayoi"). The album doesn't suffer from the removal.
 * Concept Album: Touhou Bubbling Underground revolves around Marisa and Nitori club-hopping in the underground hell.
 * Deranged Animation: "It doesn't stop at the affected area, but goes deep inside and Aah Aaahn ~ The Final Udongein", a hardcore remix of Reisen's Leitmotif. The two below-mentioned "Ecstasy" videos also have this going on.
 * Filk Song: What IOSYS's work can be considered as, in a broad sense. In a more narrow sense, a number of their songs are in the parody-filk style -- see the Trivia page for a list.
 * Funny Background Event: Well, funny and subliminally nightmarish.
 * Girls Love: A few of their music videos, most notably "Marisa Stole the Precious Thing". The Yuri level is also fairly prominent in "Remirya@Full Moon".
 * Gratuitous English: Not really any more than most other Japanese pop-music groups, but credit goes to "Special Ability to Sing a Love Spell", whose Gratuitous English is to the point that you can't even distinguish it as such without the CD liner notes.
 * Also of note is "Reason to Fly", for having only the first two words being comprehensible.
 * "Marisa Stole the Precious Thing" deserves mention for having gratuitous English, Chinese, and German all in the first verse!
 * Intercourse With You: "Border of Extacy" and "Ecstasy Masochistic" take this to over-the-top levels.
 * Covert Pervert:.
 * Kanji Salad Album Title: The kanji for Chotto Matten, Unfufuufu, Souyuu Shimpi were randomly chosen for their pronunciation, and make absolutely no literal sense whatsoever. To date, only one of these titles, Souyuu Shimpi has had a literal translation done to show how non-sensical they are (Eastern Thoughtfully Deep Forest Chicks).
 * Last Note Nightmare: "Blue Cirno", "Marisa Stole the Precious Thing".
 * Long Title: Several, which only get longer when the songs are themselves remixed, but the prize goes to the Nico Nico Douga parody "[Singing Attempt] The Brides that Queue Up the Affected Area are Impending the Precious Sun, Perfect Ignorant Fools! [Prismriver]", a medley of several of IOSYS's most popular songs, as performed by the Prismriver sisters.
 * Memetic Mutation: IOSYS's more popular works, in addition to contributing to the aforementioned Alternate Character Interpretation, tend to generate memes within the Touhou community.
 * Not just within the Touhou community, FOE!!
 * Mohs Scale of Rock and Metal Hardness: Most of their songs rate 4 on this scale.
 * Motor Mouth: Murasame United has some insanely fast rapping, in one segment starting at 1:07 and again at 1:55.
 * No Export for You: There's nothing stopping non-Japanese Touhou fans from buying IOSYS's music... except for the one minor detail that almost none of the stores that stock their material (including their own) ship internationally. Mandarake is about the only online retailer that (a) carries their music and (b) does ship to the U.S.
 * Rearrange the Song: Pretty much their forte.
 * Shout Out: Reimu lists off lots of fictional currency in "Donations <3 Please," including Keros, Dedens, Gil, Zenny, and Mels. (She also mentions Rupees, but they're the actual currency of India.)
 * Theme Naming: Each of IOSYS's album names (until Bloom) contains a kanji that refers to a character from the series Rozen Maiden. See the Touhou Wiki page for more information.
 * The group name itself might as well be named after a file named io.sys in the Windows OS. Plays nicely to their official website, which is named iosysos.com