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??
Japan Explained FASAQ 
crella said,
January 17, 2009 at 12:17 pm
Women not being able to inherit was one reason, cementing ties between allies was another. My mother-in-law’s four siblings, including the chonan, all died before she got into high school. To continue the family line ( which according to local lore, continues from a retainer of Yoshistune who was wounded in battle, could not continue to fight and remained behind after the battle of 108 flags in present Kato-shi in Hyogo-ken) MIL had to marry a ‘mukou-yoshi’ or adopted husband. Her husband (my father-in-law) married into her family and changed his name upon marriage.
In the feudal era, having a son (jinan, san-nan) go to another house as an adopted son ensured that that particular clan would not turn against you in conflict.
alexcase said,
January 21, 2009 at 1:59 pm
Perceptive and informative comments as ever Crella. I’d never thought of the cementing ties thing. Still, Koreans had even stronger clans but the fact that the (real) son had to do the ancestral rites meant adoption was and still is to a large extent a no-no.
Does the mukou-yoshi do the ancestral rights in the adopted family as usual in Japan, I wonder?
crella said,
April 18, 2009 at 3:56 pm
FIL took responsibility for the household as the chonan would. He took care of the cemetary, butsudan, and lead the prayers at Obon and at houji. I don’t know about other families though.
Adoption isn’t all that popular here, either. The mukou-yoshi and other adoptions are for the benefit of the continuance of the household and it’s adults being adopted. Adoption of small children is not as popular as it is in the US. It is considered very important to have children of one’s own blood. Once it’s apparent that there will be no children, or like my MIL’s case the chonan dies, the adoption takes place when the woman reaches an age to marry. It’s preferable to the family dying out.
One other instance I’ve seen (recently) is an elderly childless couple adopting a nephew so that there is someone to inherit property. Children can inherit somewhere in the neighborhood of 5,000 man without paying inheritance tax…were the property left to those relatives without going through the adoption, they’d lose a lot .
alexcase said,
April 18, 2009 at 11:34 pm
The tax thing could be a huge influence, of course. I wonder if it that goes back to Tokugawa times
crella said,
April 19, 2009 at 6:30 am
With Atsu Hime, and the new NHK Taiga (the name escapes me) you can see examples of children being adopted out to/married into clans to cement ties between allies.Atsu Hime was sent into the Tokugawa household as a bride (marriages and adoptions were carried out for similar reasons)to assure good relations between Satsuma and the Tokugawa family. I’ve seen the new drama only a couple of times, but in the first episode the jinan of a retainer’s family (related) was sent to become the son of their lord.(If I’d watched it enough I could give more details correct me, anyone, if I’ve got it balled up :-D) It was so sad… the poor little tyke, although well-cared for, missed his mother and trudged through deep snow to get back to his home. Upon his arrival his mother hugged him to bits, warmed him up and told him go back *weep weep* that he was no longer their son.
In the Tokugawa era, wealthy men had concubines and pretty much had scads of kids running around, one or the other was made the official heir. I don’t know what the common folk did.
crella said,
April 19, 2009 at 11:25 am
Sorry, I’ve just watched it again, he was sent to serve him, not to be adopted. My bad!
Blogging Anecdotes of Oyasama 41 | Tenrikyology said,
March 10, 2012 at 9:39 am
[…] [4] This refers to the traditional Japanese practice of adopting a male heir through marriage. (I’m assuming that Zensuke married into the Nakata family.) Here is a link to a webpage describing the practice as it was done in the feudal period. […]