I can't think of the chicks name but she's really hot (and the movie opens with a gratuitous ass-shot too!).
Bill Murray is usually fun to watch regardless of how poor the material is.
But for a love story to work, I think you have to be rooting for the main characters to hook up and live happily ever after, blah blah blah, even if it's obvious they won't. I never felt like that here and for that reason I think the movie failed as a romance.
What about comedy? Well, it really wasn't funny either. Most of the jokes were pretty cheap. Stuff like how hilarious it is that the Japanese are short and speak differently. Hardy har har...
The real star of the movie for me was the footage of Tokyo. Much of the film was shot in Shibuya and Shinjuku (where my friend used to work and apparently she could have tried out to be an extra in this movie, but didn't want to stay out that late as they were shooting 12-4am!!
) It really made me want to go back over there sometime soon. 
If you have time to kill and wanna get a good look at a couple of the more prominent areas of Tokyo, than definitely head on out to see this one. Otherwise, wait for video or cable.