Supercell Feat. Hatsune Miku
Supercell is a musical/illustration group from Japan. Ryo is the composer and lyricists of this group. He uses a vocaloid called Hatsune Miku http://en.wikipedia.org/wiki/Vocaloid.
Official website: http://www.supercell.jp
Official blog: http://supercell.sc
Wikipedia: http://en.wikipedia.org/wiki/Supercell_(band)