Very Nice!

I love this picture!
This pic needs NO work, Its perfect.
The motion in the background makes the character look like he's moving. Very nicely done. Plus, Very nice job on the character too!

Keep up the amazing work!

You might need to revise this, a lot.

First off the background is horrendous. I think you trying to make it look like he was falling but still in control (which rarely happens) so you blurred the background but it looks really bad. The design of the character looks like a combination of Samurai Champloo & Kingdom Hearts which really doesn't work. It looks like you tried to make him look hip but still maintain the fact he's a samurai. Or at least a samurai in training.
Anatomically wise it's not the worst but still needs some work. His upper torso, specifically the shoulders are a little wide and with the short shirt look like he's wearing some type of football pads. Maybe it's because his right shoulder looks like it's been dislocated. The face is just...sloppy. He has a giant forehead, the nose is a little small seeing how low his mouth is. And his ears are too small in relation to the eyes & nose. Also his left arm is positioned very uncomfortably. Not too mention the legs are a little weird.
His accessories/clothing are probably his worst features. The sword doesn't look like it matches the shape of his sheath. You should probably work on that shape because his sword right now looks very lame. His shirt is very ugly, just change it. The hakama is cool but you might need to work on the draping. The wrappings are weird and that shit would not be helpful in a fight because I'd try to grab him and strangle him with it, that'd probably break his arm as well seeing as where they're wrapped. The sheath and the sandals are basically the only thing I don't have a problem with in this picture. But you have a potential. You should probably work on anatomy and creativity and you'll be fine. Good luck!