Japanese adult adoption

Japanese adult adoption is the practice in Japan of legally and socially accepting a nonconsanguineal adult into an offspring role of a family. The centuries-old practice was developed as a mechanism for families to extend their family name, estate and ancestry without an unwieldy reliance on blood lines. Still common today, adult adoption is a dynamic tool for social and economic mobility.

There is evidence that this practice began as early as sometime in the 13th century within the sect of Buddhism known as Pure Land Buddhism, but only really became widely used in the Tokugawa shogunate (or Edo period), which began around 1600 and lasted until 1868. During the Tokugawa period, much of the Samurai class would adopt sons for the purpose of creating a strong, fixed position in society through the assumption of positions such as the head of household and the head of the business. It also was a way for households lacking in sons to continue a patrilineal line, and remain a functioning societal power. This was its most common purpose, but was also seen by the adoptees as a way to climb the social ladder by leaving the title of second son, etc. behind.