Hello. These are good.
*selout. Too much to go from pure white to pure black and then to white again. Take a step off of it where it's hit by light.
*Neat palette. Especially love the big face one.
*fourth from the right, the neck has a bulge. Iron it out pretty easily though.
*second from the right: leaning forward too much. Move everything from the waist up two pixels to the right, and then from the neck up, another pixel.
*third from the right: the vertical line on the right foot doesn't do it in 3/4ish perspective. Add a curve like on the front view to the kimono. Also, sword scabbard should be a few pixels more foreshortened, given the second one.
*fourth from the right: sleeves of uneven length, and the right one curves out about 2 to 3 pixels too much. Reign it in a bit.
That's it. I love how it's cartoony, but shaded like a fighter sprite, so to speak. Nice work. Post more, please. Have a goat.