VOCALOID, as you know, is a voice synthesizing application that have been sold commercially since 2004. And usually, the Vocaloid engine has a mascot/avatar/personna which is also called "VOCALOID(s)". Not all Vocaloids have a physical form. And some mascot of the vocaloid engine have a biography included with their package while others leave only vague hints or none at all. The mascot has no effect on the software itself and is done purely for decorative reasons.
For example, as you know Hatsune Miku has a masot of a girl with a turquoise hair, and Kagamine Rin has a mascot of 14 year old girl with short blonde hair wearing white headbands.
VY1 has a mascot, but it is not a person, unlike many other Vocaloid mascots. It is a hair pin and represents the Vocaloid2 package, and a more elaborate version for VY1v3. So, if you find a mascot of VY1 as a person or a girl, it is not offically true. It's probably just a fan made.
And all the characters and vocaloid's biography told here is actually refered to mascots of Vocaloids. You can read their biography by searching on the searching box or just click some links provided.