“…In Okinawa, as elsewhere in Japan, the individual validation of age is based on the koseki, a family register containing records of all members of a family, including gender, dates and places of birth, names of parents, dates of marriage and divorce if any, date and place of death (Saito 2010). Unfortunately, for privacy reasons, data extracted from the koseki such as birth and death records are only accessible by directly asking the relatives of the concerned persons or for official legal proceedings (Willcox et al 2008).…”