Do some cost-benefit analysis; if the university offers courses or a program that would be beneficial to you (and would prove to be a worthwhile return of investment), then I'd say it's worth it. If you have a career set ahead of you and you want to study in Japan, but that year wouldn't really help your education goals or career path, then I wouldn't recommend it.
If the goal is to just live in Japan for a while, there are a variety of ways to do that, but you probably won't be working (and especially not in your chosen profession), so be aware that it could be a very expensive decision.