Not a problem. Here's a link to the shikishi that I have posted in my gallery -
http://cutiebunny.rubberslug.com/gallery/master_query.asp?SeriesID=34938
Shikishi are small signboards that are given to famous people in Japan to sign/draw. A lot of Japanese magazines (ie. Jump Square, etc) run promotions where you can win signed items (generally shikishi, but sometimes other signed items or, around the New Year, postcards). Unfortunately, you need to reside in Japan to participate. So, really, all you would have to do is head to a konbini, see if any of the monthly mags are running a contest, and send it in.
Also, there are events where artists sign stuff, but unless you're going to be by one of the larger cities (ie. Tokyo, Osaka, Kanazawa), it doesn't make sense to do it. Train/air travel in Japan can be pricey.