livetune is a music creator who makes songs which focus mainly with having Hatsune Miku vocals, though lately they’ve done a collaboration with doujin vocalist ココ (Koko).
livetune used to consist of two members - ‘kz’ and ‘Kajyuki’ (かじゅき); before the latter left to work at Capcom. Now kz makes up the entirety of livetune.

livetune on Last.fm.