I quite like the poses and expressions used in your Mir and Yuuka sketches and I think your second Youmo sketch looks great.
By the way, since you mention music occasionally, I was wondering if you'd mind telling us who the first artist/group you first really got into was. The first singer/group that I took the effort to track down all the works of is Shiina Ringo/Tokyo Jihen.
Spoiler
http://www.youtube.com/watch?v=elWP1i9IPko
I found this song really catchy when I first heard it.
http://www.youtube.com/watch?v=yN7DmZlxO_0
http://www.youtube.com/watch?v=HOpBJ7G0YIE
http://www.youtube.com/watch?v=MqekZgfaEPM
http://www.youtube.com/watch?v=GvvvwNKdeps
http://www.youtube.com/watch?v=kBd5cvnwJZQ
http://www.youtube.com/watch?v=gLC-fLdbzuY