Hatsune Miku
One of the Vocaloid compilations, "Exit Tunes Presents Vocalogenesis feat. Hatsune Miku", debuted at number-one on the Japanese weekly Oricon album charts dated May 31, 2010, becoming the first Vocaloid album ever to top the charts. Another album, "Supercell", by the group Supercell also features a number of songs using Vocaloids. Other albums, such as 19's Sound Factory's "First Sound Story" and Livetune's" Re:package", and "Re:Mikus" also feature Miku's voice. Other uses of Miku include the albums by Absorb and by OSTER-project. She had sung the original Nyan Cat called "Nyanyanyanyan!" by daniwell-P. Kagamine Len and Rin's songs were covered by Asami Shimoda in the album "Prism" credited to "Kagamine Rin/Len feat. Asami Shimoda". Another song original sung by Miku, "Color", was covered by Maria, and featured as the opening theme of the 2011 anime series "Freezing".
SF-A2 Miki
Her design was unique among the VOCALOIDs. She had no references to YAMAHA based musical instruments like other VOCALOIDs and was designed to look cybernetic, giving her a more sci-fi look than most other Vocaloids at the time. According to information that came from the 2012 redesign, miki was designed to look like she was made out of an inorganic material and was conceptualized as an android. Her body is designed to look like that of a child, but also give her the overall appearance of a young teenage female. Though she is an android, she is covered in muscles made from various materials such as carbon nanotubes, but were made loose to give a mild deformed look about them. Having an immature-looking body allowed her to appear younger than she looks, similar to how Hatsune Miku and Kagamine Rin could do the same.