Especially the internationally unusual but still existing habit of adopting a son-in-law into a family to be the head of a household with no sons or no sons who want to take over the family business. It would seem to be anti-Confucian, Confucianism being often given as a reason for the lack of adoptions in Korea. No idea, not even many possible ideas, just the one so far:
Made acceptable by the legal need for each household (“ie”) to have a male head, unlike in Korea where family connections were larger and the head of a clan was head of a much larger group??
