Ive never seen the anime, but after this piece of work i think i might start watching it I absolutely adore the way you drew her hair and how she has a serious/annoyed facial expression, and i love the way you colored her hair, the shading is nice and light and not overwhelming (: awesome job!
It's Kagari! I love this anime! I really hated her in the beginning, but she gets nicer towards the end (I haven't finished watching it, so, yeah) I have to say you coloured her hair a little too dark, but it still looks good!
Proportion my friend I suggest working on drawing real people and then go back to anime. It really helps, no joke. After you get better at drawing real people your anime becomes sooooo much better. Afterall, anime is just a representation of real people. ;D
I agree with what else has been said, that you could definitely use more shadows. :3 Try using several different shades to build up a nice gradient, and make sure you don't allow the paper to fully dry before you're finished coloring each section, because that way you won't end up with streaks. :3