Very NICE! I just started drawing danny myself. i couldn't figure out SAI, and went with manga studio instead. I might have to give SAI another try, i like your shadow and lighting! Are you using a tablet, or just your mouse to draw?
It took me a while to figure SAI out. I went through tons of tutorials and with the help of some really great people here on DA, I'm starting to get used to it (: & Thank you <3 I use my tablet to draw C: