actually not just korea but any other countries too and those without same sex marriage, it common for people to be adopted by the older partner. This is the only way for them to be family and get same rights as biological family members, including automatic inheritance rights, hospital visitation, and the ability to make medical decisions.
Is adopting an adult in korea a legal thing.
I think as long as you can prove that you are older than them you can submit the papers.
actually not just korea but any other countries too and those without same sex marriage, it common for people to be adopted by the older partner. This is the only way for them to be family and get same rights as biological family members, including automatic inheritance rights, hospital visitation, and the ability to make medical decisions.