My husband and I are preparing to move to Japan also and going through the same things.
Make sure you get your marriage registered and onto your husband's koseki in Japan, because you need that to get the spouse visa.
We didn't do it right away, since we weren't thinking about ever living in Japan at the time. But once we decided to and started doing visa things, we had to register me on the koseki, went to the marriage registration place in his hometown and got the paperwork and copies of my passport, etc., BUT since we waited a while, we couldn't use the marriage license we had (as it had to be less than three months old, I think) and instead had to go back home and get a more recent one issued, and now we've sent that back to Japan with all the paperwork to finish filing the marriage (having his parents do it for us). So anyway, just be sure you register the marriage in Japan soon, otherwise it'll be more difficult to go back and do later!