Anime girl with long blue hair?

I don't think she's technically from an anime, but it's some chinese or Japanese software where you can make the character dance to a song or something? Well my friend showed me some youtube videos of the characters and I want to watch them again, one of the girls has long, they go almost to the floor, blue pigtails, and another has a blond side ponytail. Someone help me please! Oh, and I think the name of the program or anime or whatever started with v, or vo, or vu or something, thank you so much for the help!