Destination - Legal Marriage in Sapporo

I and my partner will go to Sapporo at the end of the year (December 23 ~ Jan 7/2018). We are planning to have legal marriage in Sapporo- Japan. We are both US Citizen and living in US.
First, we know we have to take an appointment with the US Consulate to sign the form Affidavit of Compentency to Marry. Second,we will turn Kon-in Todoke. Where should we go to? Shiyakusho? or KUyakusho? We are thinking to turn the Kon-in Todoke in January 4th, 2018. Third, we have to ask them to give us the Certificate of Acceptance of Notification of Marriage (Kon-in Todoke Juri Shomeisho). Is there anyone know... how long does it take to receive it after turning Kon-in Todoke? We need to have it before
Your answers are greatly appreciated.

You should really contact the city in advance; I don't think they will be too pleased to see two non-Japanese-speaking foreigners coming out of the blue to do marriage paperwork.

Do either of you have Japanese ancestry and that's why you're wanting to get married in Japan? Why not just do the ceremony here for fun and leave the legalities for the US? I don't really understand why 2 tourists, who otherwise have NOTHING to do with Japan, would want to get legally married here. You understand that you wont be getting a useful marriage certificate right? It'll be in Japanese, and you'll always have to get it translated and explain everything any time you need to use it. Getting your name change has to be done through the US anyway, too. So what's the point?

Basically, you're causing a lot of trouble for staff at city hall to marry 2 tourists who have nothing to do with that city or even the country, and for yourselves in the future any time you need to show your certificate or for the name change.

So seriously, please explain to me the point?

I am Japanese speaker. I posted to ask how.... and I don't think I need to explain anything... don't be hassle like that! Duh!

Then you can look this up on the city's website yourself.

The marriage is legal here as it is in the USA (and internationally) - I worked through this for a couple last year and it was easier in Tokyo where they dealt with non-Japanese more often. but giving an office in Sapporo advance warning would be useful. (I am helping with another one in October.)

BTW, for the affidavit they (the embassy) needed a local address - do you have one?
and,
Do you have your document translations sorted out?

Once all the docs were sorted, the whole process (including getting the certificate (the optional extra) was about an hour, but we did it across two days with a week in-between.

I am Japanese speaker.

Then why are you asking about getting a marriage certificate in Japanese, in Japan, on a forum in English? Call city hall yourself to ask them directly! Duh!