It's been years. Mina's whole being seems to be light and bright again, even without the presence of Chaeyoung. (Or alternatively, Chaeyoung visited Mina in her dreams for the first time to tell her that she can now let go because she is now okay and in good hands already.)

Chaeyoung is the one that fills the emptiness in Mina, yet the latter still chose not to be with her until the end, but it’s okay, Chaeyoung understands, after all, she’s with Mina through all the way.

Chaeyoung just wanted her family to be complete, but destiny won't let her, will never be.