I've never used the search but from playing with it it looks like it will either search the web (kinda defeats the purpose) or the loaded guide. So if you load the Tokyo guide that will help however having a quick look at it I have to say it's a bit rubbish, there's just not that many places in it. Probably the best bet is to add your own bookmarks to places you know you want to have marked so then they'll be available once you're there.