this was beautiful. i didn’t fully understand the adoption papers though

Its the only way they can legally be a family. Like say one of them gets sick and only family can visit. Or one dies and they cant pass along their belongings unless theyre family. Im assuming its a common practice in korea

Basically what the other comment says. It's pretty common in countries where gay marriage isn't allowed so that partners can make legal and medical decisions the same way a spouse would.