NICE......
Though Nene's skirt looks a little funny.
Either leave her without the skirt and stylish panties or a full skirt.
That's my advice.
You know...in allot of Japan anime, allot of manga girls wear "Metal-Armored-Undies" a reference is Tron Bone of the Megaman Legend series.
The rest of the characters look great though I feel too much "blue" is used here.
The building could afford to be a different color from each other and I feel it wouldn't interfere with the composition.
If you want the Graffiti to look realistic, make it look more worn out.
Cause right now it looks kinda sticker-ed on.
I'm not trying to be nit picky, it's just a few points away from perfection in my opinion.