[typing]

This is all heresay but...

Marrage only will get you a spousal visa, having a spousal visa will make getting the citizenship a little easier (because those are 10 year ((5??)) visas and it will take you that long to get the citizenship)

Being Fluent, like REALLY fluent in Japanese will help since there is assloads of paperwork involved and while they will have someone to help you, you make one little mistake because they couldn't explain it right, you start back from square one. (And Government traslaters, as far as I've seen so far in dealing with them, really suck.)

I believe you have to have resided in Japan for 3 or 5 years before your eligable for the citizenship, and you have to give up citizenship to your birth country (so no dule visa's)

The downside of all this is even if you become a Japanese citizen, you, your children and your grandchildren, will always be "Gaijin" or somewhere down the line if your grandchildren are lucky they'll be "Halfs"

As much as I love Japan I'm not even going to bother trying to become a citizen, too much of a hassle and I'll never be treated equil anyway.