I'm sure what you were going for is the cutesy outer shell with a gooey psychotic center. However, the only thing that really shows me she's a little not right in the head is the blood spattered background. If you didn't tell me she was a "yandere", I probably wouldn't have known!
Cute cat girls that are a little crazy obviously isn't the most original thing in the world, but it doesn't make it any less of a good idea.
The lineart is very smooth, but the shading can leave a little more to be desired. I see it's mostly cell shading and soft brush shading. Adding more tones to her hair, the front of her dress ( the lace going down the front looks very flat without any shading, as do the buttons ) and to her face will give it more depth and "wow" factor. Pick a skin tone, then a shading tone, then a DARKER shading tone to give a little more to overall look of your shading. Same applies to hair, clothes, etc. Also, from what I can see your light source is the upper left of the picture, don't forget to shade your character in accordance to your light source!
Your anatomy is decent, except for her arms. The right upper arm ( the part that comes out of your shoulders ) needs to be shortened EVER so slightly, and the forearm made a bit longer. Same applies to the left arm, but the way it's bent makes it look like her forearm is curved like a crescent, rather than straight. Looking up ref pictures or foreshortening tutorials will help out with that ^ ^
Overall it's not a bad piece. The character is very cute and her outfit is also. I'd also suggest you work a little more on the background to pull the piece together as one. Either add a simple pattern or draw the background yourself, because the way your character is drawn and shaded doesn't really fit with the background you chose, and they look like they're apart of 2 completely different things. I personally hate backgrounds, so if you do too, I know how you feel, but practice makes perfect.
I hope I helped you out a little!
detailed bias-less critique, honestly its amazed me. especially on the shadowing part, yes, the front lace seems flat (xD result of rushing work), and yes, some parts need to be darker to produce more depth on it. anatomy has been my biggest weakness (well, being said, everyone has hat kind of problem xD), and thanks for taking your time giving your thought on this work :]
I think some of the ideas there were intentional, I think it's not very fair criticism.
given variety shading style, its acceptable. its just my style of simple shading, complex shading can be more darker to give more realistic feeling
I agree with the shading ideas, and I don't know if it was intentional or not? But Overall a good piece. I love the char