- First of all, when are you getting married? I'm asking because you say you join her when you marry. I want to be sure that you will be married before the current visa expires, because there is no "fiance" visa for Japan.
- As long as you get married (meaning with all documents in place) before you apply, and apply for visa status change and have it accepted before the current visa expires, it's OK :)
- 3) would not be outright illegal, but comes close to a false statement, so I would not recommend it.
- If you do 1), then you will have to go back to the previous prefecture to pick up the visa.
- Since you will be living with your Japanese wife in the new prefecture, it would be natural to do it as in 2). But are you sure that you can get all the documents together and apply on the day of your move? That sounds very busy, considering you have to move, go to city hall to report the address change, get your papers and go to Immigration on the same day?
- You need to submit your Japanese wife's "koseki" with her marriage to you stated in it, and her "juminhyo" preferably with your name also appearing there as "de facto head of household." (See the link below to find out exactly what documents you need to take). So all those paperwork has to be done in order for your application to be accepted.
- Take into consideration that it looks "nicer" to Immigration if the two of you appear together at Immigration office to apply. There could be question about why you've had different addresses, etc., so in that case it is better that the couple goes together. So (I know this is not a requirement at all but) arrange to do that if you can.
About application for change of status of residence:
http://www.moj.go.jp/ONLINE/IMMIGRATION/16-2.htmlFor spouse of Japanese national, there seems to be a questionnaire document (one I haven't seen before) about when and where you met, and all that.
Equivalent page in English, somewhat abridged:
http://www.immi-moj.go.jp/english/tetuduki/kanri/shyoru...