Learn the requirements and how to apply for a marriage license. Marriage License Services are offered Monday to Friday from 8 AM – PM.If you are a US citizen and are planning to get married in Japan, you will need to fill out an "Affidavit of Competency to Marry," using this form (PDF 158KB). An affidavit is a sworn statement of fact that can be used in a variety of legal proceedings, from bankruptcy cases to family and civil litigation matters. Couples may schedule with the Santa Clara County Clerk-Recorder's office to have a civil wedding ceremony held in a private and decorated ceremony room. What does Affidavit mean? An affidavit of marriage is a legal document and a sworn statement submitted to the court or another institution, to verify that two people are married.