The Unofficial Hatsune Mix book has spent five weeks on the New York Times bestseller list for mangas. Both the story and the artwork were created by Kei; this artist developed the original illustration for Hatsune Miku.
According to the press release, this omnibus stars the popular Japanese vocaloid and several supporting characters including Rin, Len, and Luka. Dark Horse Comics published this book back in September 2014.