Our son wanted to be a ninja at first but realized that he was a ninja for a previous halloween.  We showed him a picture of a samurai and he said that was what he wanted to be.  After several design options his Dad found some old folders that looked leatherlike and were pretty stiff.  He looked at photos of samurai armor and designed it to look like the real thing.  All of the pieces were cut out of the folders and sewed together with paracord.  The whole costume is made from the folders except the hard hat part which his dad had used when he worked construction, we just painted it red with spraypaint.  We got a lot of different ideas and let our son pick out all of the add on designs.  The katana sword and knife  is made from a meter stick and ruler covered in duct tape with paracord wrapping on the handle that his Dad did.  Our local mall has a trick or treat event and we went there.  There were hundreds of people there and EVERYONE was staring and saying Oh My Gosh that is amazing.  Several people stopped us to get photos and one lady had saved her last piece of candy for the best costume she saw during the night and she gave it to our son.  We were hoping to enter him into a contest but they did not have one there.  He would be so happy to win a costume contest. He was so proud of his costume he kept it and plays in it all the time.