Okay...don't hurt me for using the Mickey Mouse picture as an example, but I couldn't find anything else off hand.
Anyways - if you're making something you've NEVER tried making before, a simple, easy way to achieve a good costume without putting too much brain power into it would be to find something that probably has a pattern available and modify that. In this case the first thing that came to mind for me would be like the safari outfit there, since I'm sure it'd be pretty easy to find a pattern for that. Minor adjustments, of course, will need to be made.
First, and probably most obviously, would be the fact that you don't need all those pockets. Good. =D So nix the pockets. Second, you'll be substituting a zipper for buttons (which means the jacket will be a couple inches less wide). Third, you'll be subsituting Neji's collar for the collar in the picture. This is where the very roughly drawn collar at the bottom of the picture comes into play.
You'll need 2 pieces of the same shape (they'll need to be mirror images of one another to get a clean seam), and some fabric interfacing (iron on stuff that you put on the back of collars to get them to stand up like Neji's). My idea would be as such: Iron the interfacing onto the back of the 2 pieces of the collar, then sew them together and attach to the jacket. =3 Hopefully it'll come out nice. You can also probably sandwich a stiffer piece of cloth or padding into the collar, but I'm not sure how good the results would be. It depends on what you want to do, really. Anyways. After that, it's all a matter of attaching the collar to the jacket and adding the zipper. ^_^
I hope that was of some help. Good luck!
