I think the character is lovely, but I have a problem with the background. The 45° line of the building hints at an oblique perspective, but then you shouldn't see the sky at all... I guess removing that line would make it side-view.
With these colors available, in the blank space I would have made a horizon line that shows typical japanese silhouettes : either traditional buildings or mountain ranges. "Mist" is a good excuse for not detailing :)
that's a really nice piece, but I can't understand the postrure of the left arm...
the character looks nice, but that sword is way too long and thick.