Maybe instead of graduate from college -> live in Japan, I'd recommend doing an exchange year (or a semester) during college and see how you like it. Only after then, consider getting a job in Japan. Though, keep in mind that if you do an exchange, the university in Japan will usually help you a lot (especially if you're a graduate student), with things like a apartment/(dorm), and bureaucratic things, at least from my experience.
It'd be another thing going on your own looking for a job. Some of the universities with international programs will also aid you job-hunting in Japan (at least mine had the offer, so I reckon others would too), so doing an exchange in your last year could be an idea.
