Hatsune Miku is a female persona developed by a Japanese company using synthesizing voice technology (Vocaloid 2 speech synthesis engine ).
"Hatsune Muku" can roughly be translated as "First Sound of the Future".
Have a look....
I saw from a video posted by Ann O'Toole that Gantz Nishi sold a Hatsune Miku avatar and so had to go and get one!
These photos were taken at a sim called "Daytime Dreams" which has many visually interesting pieces.