> Only in Japan does the adoption make it a family or lineage thing.

No. Every culture worldwide accepts adoption. A child, grandchild, nephew, etc, continuing a business keeps the business in the family. Whether the child is adopted or not, and regardless of the age of adoption.

You’re not understanding the difference: in most of the world, businesses are carried on because there’s some financial value derived from it, not for the thing itself. Family businesses do exist, and do get passed down, but if the owners of the business don’t have any natural heirs, they’ll wrap it up or sell it. That’s normal.

In Japan, the longevity of the thing has a value of its own, so much so that they’ve invented adult “adoptions”, simply to keep an old business going. The business could be mediocre and barely profitable, but if it’s 300 years old, they’ll find a way to keep that line going.

Maybe they exist, but I’m not aware of any other culture that has taken up the practice of adopting adult males to ensure that a family business remains “family”.

I agree but I think regardless of profitability keeping small/medium businesses around is not just the for the longevity bragging rights. Some of these businesses preserve arts, techniques, handcrafts, recipes etc that might have otherwise been lost. And there is something to be said for street level neighborhood character created by these stores.

Something but...what?

Tge street-level character of a city isn't magically preserved because the acquiring company chose to retain the name. Example: I live near a sushi restaurant that has changed hands six times in my life. Two times they kept the name. One time they kept the facade. Never did they keep the employees. Maybe a token "manager" but the character of the place always shifts.

I like the metaphor because it really does ask the question "how much must one replace to make something indistinguishable from its progenitor?"

These are not the businesses we're looking for.

Adult adoptions to pass on family businesses large and small are somewhat common in Germany. Mostly it's used to save on taxes (nobody cares about the difference of sale and that kind of inheritance) however officially this can't be your (only) reason for adoption. That e.g. got the Darboven and Jacobs families into trouble who wanted to merge their coffee dynasties by adult adoption.

Ancient China also had this kind of tradition.

> regardless of the age of adoption

Are adult adoptions common at all?

Becoming a son-in-law or daughter-in-law certainly counts in this context.

This is apparently a very common thing in farming.

Pretty common to save tax on inheritance I'd say.

it is quite common in the part of India where I come from.

The relentless attack on the family in the West may also be related

Huh?