Before the World War II, it was a simple matter to change one's family name or adopt a child, and there were no problems involved in the process, but after the World War II, the civil law was revised and the permission of a family court became necessary in order to change one's family name.
戦前は改姓や養子縁組が容易に行えたため、改姓に際する問題はなかったが、戦後の民法改正によって改姓の際に家庭裁判所の許可が必要となった。