is a Japanese musical ensemble and dōjin

Dojin

, often romanized as doujin, is a general Japanese term for a group of people or friends who share an interest, activity, hobbies, or achievement...

 circle from Sapporo, Japan. The group is primarily known for producing remixes of music from the Touhou Project

Touhou Project

The , also known as Toho Project or Project Shrine Maiden, is a Japanese dōjin game series focused on bullet hell shooters made by the one-man developer Team Shanghai Alice, whose sole member, known as ZUN, is responsible for all the graphics, music, and programming for the most part...

 series of dōjin games. They are not signed to a label, instead preferring to release their music through dōjin

Dojin

, often romanized as doujin, is a general Japanese term for a group of people or friends who share an interest, activity, hobbies, or achievement...

 channels such as the Comiket

Comiket

, otherwise known as the , is the world's largest self-published comic book fair, held twice a year in Tokyo, Japan. The first Comiket was held on December 21, 1975, with only about 32 participating circles and an estimated 600 attendees. Attendance has since swelled to over a half million people....

 convention and via their website. Their music frequently parodies characters or themes of games such as those of Touhou Project

Touhou Project

The , also known as Toho Project or Project Shrine Maiden, is a Japanese dōjin game series focused on bullet hell shooters made by the one-man developer Team Shanghai Alice, whose sole member, known as ZUN, is responsible for all the graphics, music, and programming for the most part...

 or Atlus

Atlus

is a Japanese computer and video game developer, publisher, and distributor based in Tokyo, Japan, best known for developing the console role-playing game franchise Megami Tensei. The first Megami Tensei was a Nintendo Entertainment System video game published by Namco based on a trilogy of...

's Etrian Odyssey

Etrian Odyssey

Media Create/Famitsū reported that Etrian Odyssey had sold 119,584 copies in Japan as of July 1, 2007. Atlus' own July 2007 investors report listed US sales of the title at around 30,000 units, roughly 2 months after release....

. Many of the current members reside in the Hokkaidō

Hokkaido

, formerly known as Ezo, Yezo, Yeso, or Yesso, is Japan's second largest island; it is also the largest and northernmost of Japan's 47 prefectural-level subdivisions. The Tsugaru Strait separates Hokkaido from Honshu, although the two islands are connected by the underwater railway Seikan Tunnel...

 or Kantō areas of Japan.

The name is possibly a reference to the io.sys

IO.SYS

IO.SYS is an essential part of MS-DOS and Windows 9x. It contains the default MS-DOS device drivers and the DOS initialization program.- Boot sequence :...

 system file.

Flash videos

IOSYS is generally best known for the Flash

Adobe Flash

Adobe Flash is a multimedia platform used to add animation, video, and interactivity to web pages. Flash is frequently used for advertisements, games and flash animations for broadcast...

 movies that go along with their songs, the most widely known of which are "" and "" (known in English speaking circles as "Overdrive"), both of which are popular on the Japanese Internet forum

Internet forum

An Internet forum, or message board, is an online discussion site where people can hold conversations in the form of posted messages. They differ from chat rooms in that messages are at least temporarily archived...

 2channel

2channel

is a Japanese textboard. In 2007 there were 2.5 million posts made every day. Launched in 1999, it has gained significant influence in Japanese society, comparable to that of traditional mass media such as television, radio, and magazines. As of 2008, the site generates revenue upwards of ¥100...

, Nico Nico Douga

Nico Nico Douga

is a popular video sharing website in Japan managed by Niwango, a subsidiary of Dwango. Its nickname is "Niconico" or "Nico-dō", where "nikoniko" is the Japanese ideophone for smiling. Nico Nico Douga is the thirteenth most visited website in Japan...

 and in other otaku

Otaku

is a Japanese term used to refer to people with obsessive interests, particularly anime, manga or video games.- Etymology :Otaku is derived from a Japanese term for another's house or family , which is also used as an honorific second-person pronoun...

 internet circles. They also produced the 2nd ending credits for Penguin Musume Heart

Penguin Musume

is a Japanese manga series, written by manga author Tetsuya Takahashi. The manga was serialized in the Japanese shōnen manga magazine Weekly Shōnen Champion between 2006 and 2007. After the manga ended serialization in Weekly Shōnen Champion, the serialization was restarted from the February 2008...

 and composed opening and ending credits music for Yumekui Merry.

Discography

The name , meaning Eastern, refers to the Touhou Project

Touhou Project

The , also known as Toho Project or Project Shrine Maiden, is a Japanese dōjin game series focused on bullet hell shooters made by the one-man developer Team Shanghai Alice, whose sole member, known as ZUN, is responsible for all the graphics, music, and programming for the most part...

 series.

Reference for discography taken from Videogame Music Database.

01. ファミコンCDDX

• Famicom CDDX
• Released May 08 2005

02. 東方風櫻宴 (Tōhō Kazakuraen)

• Phantasmagoria mystical expectation
• Released May 21 2006
• The first IOSYS Touhou Project arrangement CD, mainly instrumental. Only the first and fourth tracks having lyrics.

03. 東方乙女囃子 (Tōhō Otomebayashi)

• Touhou Maidens' Orchestra
• Released Aug 13 2006
• The Otome Bayashi includes one of IOSYS' most famous songs, "Marisa Stole the Precious Thing", but is also mainly instrumental.

04. 東方月燈籠 (Tōhō Tsukitōrō)

• Touhou Moon Lantern
• Released Dec 31 2006
• In this CD, "Stops at the affected area and immediately dissolves ~ Lunatic Udongein" is included. This is the first IOSYS CD in which every track has lyrics but the fourteenth. Was re-released in 2009 as Touhou Moon Lantern (Safe), with certain tracks added/removed.

05. 世界樹のおもちゃ箱 (Sekaiju no Omochabako)

• Yggdrasil's Toy Box
• Released Apr 30/2007

06. 東方永雀峰 (Tōhō Eijanho)

• Touhou Eternal Sparrow Peak
• Released May 20 2007
• This is a rearrange of nearly the entire Touhou Eiyashou
  Imperishable Night
  is the eighth official game of the Touhou Project scrolling shooter series by Team Shanghai Alice. It is the third Touhou game to be released specifically for the Windows operating system...
  
  soundtrack, with vocals for only 3 tracks. It also features a parody of Marisa Stole the Precious Thing

07. 東方萃翠酒酔 (Tōhō Suisuisūsū)

• Touhou Gathering Green Wine Drunkenness
• Released Aug 17 2007

08. ごっすんとかのからおけ (Gossun to ka no Karaoke)

• Released Nov 11 2007

09. 東方河想狗蒼池 (Tōhō Kasokusōchi)

• Touhou Blue Land of Rivers, Visions, and Tengu
• Released Dec 31 2007

10. ねこみことかのからおけ (Neko Miko to ka no Karaoke)

• Released Mar 03 2008

11. 東方真華神祭 (Tōhō Makashinsai)

• Touhou Splendid Divine Festival
• Released May 25 2008

12. ごっすんリミックス　アイン (Gossun Remix Ein)

• Released May 25 2008

13. ごっすんリミックス　ツバイン (Gossun Remix Zwein)

• Released May 25 2008

14. 東方想幽森雛 (Tōhō Sōyūshinpi)

• Touhou Such a Mystery
• Released Aug 17 2008

15. おさいせんとかのからおけ (Osaisen to ka no Karaoke)

• Released Oct 13 2008

16. 東方氷雪歌集 (Tōhō Hyosetsu Kashu)

• Touhou Anthology Of Ice And Snow
• Released Nov 02 2008

17. 東方泡沫天獄 (Tōhō Hōmatsu Tengoku)

• Touhou Bubbling Underground
• Released Dec 29 2008

18. 東方超都魔転 (Tōhō Chotto Matten)

• Touhou Just A Moment
• Released Mar 08 2009

19. bloom

• Released Mar 08 2009

20. 東方年柄年中 (Tōhō Nengaranenju)

• Touhou All Year Round
• Released Aug 15 2009

21. 東方JeuXinTerdiTs

• Touhou JeuXinTerdiTs
• Released Dec 12 2009

22. 東方アゲハ (Tōhō Ageha)

• Released Feb 14 2010

23. 東方銀晶天獄

• Touhou Crystallized Ocean
• Released Mar 14 2010

24. 燃えろ！東方ブラスバンド

• Moero! Touhou Brass Band
• Released May 05 2010

25 東方 Faithful Star

• Touhou Faithful Star
• Released July 11 2010

26 東方うたうチルノちゃん

• Touhou Singing Cirno chan
• Released August 14 2010

27 東方恋苺娘+

• Touhou Love Strawberry Girl +
• Released August 14 2010

28 Touhou IO-BEST BEATS

• Released September 19 2010

29 東方メリーゴーランド

• Touhou Merry-Go-Round
• Released September 19 2010

30 東方浮思戯革命

• Touhou Wonder Revolution
• Released October 11 2010

31 東方云符不普

• (title is sequence of characters that make no literal sense)
• Released December 30 2010

32. 東方メレンゲ少女夜行

• Touhou Merenge Shoujo Yakou
• Released March 13 2011