Hatsune Miku
Hatsune Miku was the first Vocaloid developed by Crypton Future Media after they handled the release of the Yamaha vocal Meiko and Kaito. The name of "Hatsune Miku" was conceived soon after the Vocaloid 2 announcements, when an English and Japanese vocal were developed for the character. The intended design was delayed and later used for Megurine Luka instead. Miku was intended to be the first of a series of Vocaloids called the ""Character Vocal Series"", which included Kagamine Rin/Len and Megurine Luka. Each had a particular concept and vocal direction.
SF-A2 Miki
SF-A2 was released the same day as Kaai Yuki and Hiyama Kiyoteru as the 3rd Ah Software Vocaloid. SF-A2 miki's direction is very different from Kaai Yuki and Hiyama Kiyoteru as she was a professional artist vocal. Much of her planning and development was handled by HEARTFAST.