I found a long piece of styrofoam lying on the ground a few blocks away one day. I wondered where the hell I could get one, and it just popped out of the ground. Somehow, I don't have a very good feel about this luck. hahahhaha.
Cut it in half and glued each piece to either side of a dowel attached to the handle. Then I realised there's still a lot of calculations to do, thinking about the cosine graph on the sword....
I put it away right before otobaka came home =A= luckey.