iosys
A Sapporo-based musical ensemble doujin group best known for remixes of music from the Touhou series.
Their song 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.
