koseki

thumb|right|Reproduction of a koseki certificate printout

A or family register is a Japanese family registry. Japanese law requires all Japanese households to make notifications of their vital records (such as births, adoptions, deaths, marriages and divorces) to their local municipal authority. Domestic aspects such as marriages, divorces, acknowledgements of paternity of non-marital children, and adoptions, are only legitimized if they are recorded on the koseki. Births and deaths become legally effective as they happen, but such events must be filed by family members or other persons as allowed by law.