I don't know if it's still a thing, but in Japan some business owners with no heir used to adopt adults for them to take over the business. It's like you said,

I don't know if it's still a thing, but in Japan some business owners with no heir used to adopt adults for them to take over the business. It's like you said, starting as an apprentice, and if the owner trust him enough he'll adopt him, the apprentice litterally taking the family name of the business owner. So it's still the same family!