Hatsune Miku, codenamed CV01, was the first Japanese VOCALOID to be both developed and distributed by Crypton future media inc. She was initially released in August 2007 for the VOCALOID2 engine and was the first member of the Character vocal series. For a variety of reasons, Miku received unexpected commercial success. Due to Miku's popularity boom, Crypton had the chance to take advantage of early technical support for Miku and several guidebooks and magazine support were released solely focused on her vocals. This type of technical coverage was even possible long after Miku's initial release and methods of adapting her vocals are the most well documented among the VOCALOID2 era vocals.