married name change

first, i should say hi to everyone, as i've never posted here before.
i'm an american guy, and i just moved to tokyo and married a japanese girl. we're living with her family, and i'm trying to figure out how to change my name to be the same as her family name. we asked at the kuyakusho (local govt office) where we did the marriage paperwork, but they didn't know. then, when we were at immigration to change my residence status and get a new visa (spouse visa), they said to ask at the ministry of justice. but i can't find any information online on their site. has anyone done this? which giant beurocratic offices should i go to, and how do i do it?
thanks everyone.

Next time have your wife come with you if she didn't before, and go to the KOSEKI-KA at the local city hall where her family is registered. Ask them. The fact that you're a foreigner, and that you didn't check this out before you got married is/are gumming this up for you.

You may be required to legally change your name in America, too. The tricky part is that you may or may not be able to legally change your name to kanji in America. If you can not do so, you most likely will not be able to change your name to your wife's name completely. You will still get the katakana treatment, because your legal name is not in kanji. Incidentally, I've seen this with Americans of Japanese ancestry before. It's a perfectly Japanese name, and the kanji it would be are easy to guess, but still, it's katakana.

Good luck! If you find out more, let us know!

In the worst case scenario, you should talk to a lawyer who is accustomed to foreigner issues. It will cost money, but s/he will give you the best advice you are likely to find anywhere.

Entirely up to you to reply, but I wondered why you wanted to change your name.
I know why my Japanese brother-in-law changed his name - because he was asked to by our father-in-law so the family name would continue. The irony is, my brother-in-law's two older married brothers are both now approaching sixty years old and are still, and will no doubt remain, childless.
But anyway. Just wondered.

so, i went to the local office yesterday. they said they didn't know about that, and we should call the ministry of justice. but the people working at the local office that day were extra friendly and helpful, so they actually called for us. however, it turns out that they can't do anything for me either. i'm gonna have to do it through the american embassy, using romaji letters. at least, until i become a citizen here eventually (if i do end up doing that). i guess it makes sense, that they don't go around changing foreigners' names without doing so in their own country. but they will marry foreigners, and doesn't that usually go along with a name change? too bad.

by the way, i wanted to change my name because it's usually easier for a married couple to have the same name, and i like japanese names. also, it would probably be more difficult for her if she had a foreign name. also, my last name is derived from an italian last name, but it became completely americanized when my ancestors immigrated to the u.s., and lost any meaning or cultural significance, so i'm not sad to lose it.