Marriage in Japan
The information below is given for American citizens, but can generally be adapted for citizens of other countries. See the relevant embassy for more information. The relevant documents, or those obtainable without visiting a government entity, are all attached below for your convenience.
1. Prepare an Affidavit of Competency to Marry, or Kon’in Yoken Gubi Shoumeisho （婚姻要件具備証明書）
This document is legal proof that you have no other marital obligations, that you are of age, and that you can be married. The form (in English) must be translated to Japanese and notarized, which can be done at an embassy. For a single spouse, use this form (also linked above and attached below). For two foreign spouses (no Japanese spouse), use this form.
If you are marrying a Japanese national, the future spouse must prepare this document in advance, obtainable at the city hall.
This document is the official marriage contract. You must have two witnesses stamp the form with their personal seal, or hanko/inkan (判子/印鑑). You can find a translation of the document here, if you need help.
Some offices require other documents, such as birth certificates or Certificate of Registered Matters, or Touroku Genpyo Kisai Jiko Shoumeisho (登録原票記載事項証明書), which is basically a proof you have an Alien Registration Card (外国人登録証). To obtain one, read more here. Contact your city hall beforehand about document requirements so that there are no unanticipated problems.
5. Get Married and Get a Certificate of Acceptance of Marriage Registration, or Kon’in Juri Shoumeisho (婚姻受理証明書)
The exact place to go in the city office is the Family Registration Section, or Koseki Gakari (戸籍係).
Make sure to keep records of your marriage. The Certificate of Acceptance of Marriage Registration is very important and is to be used for a variety of immigration and legal purposes. Fortunately, you can have the city hall print several of these, for a fee.
Although the office offers both long and short forms of the Certificate of Acceptance of Marriage Registration, you generally only need the short form of the certificate. The only difference is that the long form contains all copies of the original documents, while the short form is just a certificate. If you need a translation form, click here.