A Sapporo-based musical ensemble doujin group best known for remixes of music from the [[touhou|Touhou]] series.

Their song "魔理沙は大変なものを盗んでいきました", known in English-language fan circles and beyond as "[[Marisa Stole the Precious Thing]]" or "Marisa Stole Something Very Important", has, through its popular and memetic promotional video (post #82943), brought Touhou and the [[Alice Margatroid]]/[[Kirisame Marisa]] pairing to the attention of a huge number of people.

h4. See also

* [[IOSYS Parody]]

h4. External links

* Official website: http://www.iosysos.com/
* Touhou Wiki on IOSYS: http://en.touhouwiki.net/wiki/IOSYS