After reading many of these comments I think the ending was meant as a dream/Rara's imagination. Someone said before that they probably had a funeral and visited his grave.
I feel like him wearing black is supposed to be a hint, because why would you wear a colour signifying death when you supposedly recovered from a deadly illness?? Rara was wearing pretty dark, lifeless colours too as she said that she was still not over him. which could mean she was still not done mourning.
I think the fact that there aren't any more happy moments afterwards supports this theory too. If you really want a happy ending, why not include more scenes?
The older gentleman's storyline - he mentions that he broke up with his wife and met her again after 5 years.…
She kept checking up on him throughout the whole series. She's the lady who thought Rara and her (ex)husband were together even when Rara was already dating Jun. Then there was an 'after 5 years' part for everyone and I think that's what she's referring to, that she kept making up excuses to visit him.
I feel like him wearing black is supposed to be a hint, because why would you wear a colour signifying death when you supposedly recovered from a deadly illness?? Rara was wearing pretty dark, lifeless colours too as she said that she was still not over him. which could mean she was still not done mourning.
I think the fact that there aren't any more happy moments afterwards supports this theory too. If you really want a happy ending, why not include more scenes?