Well touristy stuff anywhere is going to be expensive, because they know people will pay for it. I can't really recommend much outside of that kind of stuff though, since I've not really experienced much of it myself.
It's either been touristy stuff or just spending time with girlfriend and her family.
I'm going to be out there from the 7th of Jan (assuming everything goes okay on this end), going to be starting up a post-doc at Osaka U.