If I buy an iphone6 unlocked in Canada, can I just buy a contract in Japan and use it?

I am looking to buy a iphone 6 from fido (carrier is fido) and then unlock in the Fall when my contract ends. After unlocking it I was hoping to take it with me to Japan in hopes of just buying a prepaid or contract in Japan and using the iphone 6 from Canada. I have no idea if that works in Japan since the cellular system is quite different. Can anyone help me out here?