Responses
What is frustrating is the imbalance. This started as Ahjussi's story. Then it ended as Yoo-Il's story. We didn't get the end of Ahjussi's "what happened later." So, it just feels incomplete. We didn't get the main character in the epilogue, so one does feel as if he dropped dead.
Ahjussi is not dead. She only told us that this was her first idea for the ending. We already saw the ending and he's still alive. They just broke up, nobody's dead, nobody killed himself. You can calm down now ;) .