Adoption

Unlike some contexts where adoption customs carry a reduced-status risk, Japan’s well-established practice of adult heir adoption (養子縁組, yōshi engumi — commonly adopting a son-in-law or capable outsider as full heir to continue a family name or business when no biological heir exists, still common in Japanese corporate succession today) is actually a helpful cultural bridge: it already carries full inheritance and family-name status, which maps well onto Romans 8’s picture of adoption bringing complete inheritance rights.