Momo

Yes he was possessed but then prof cha's soul jumped out and he couldn't finish the surgery so Seung Tak had to finish it.

Basically a happy ending. All the coma ghosts wake up except for the walnut man because he got transferred to another hospital. Prof Cha's surgery was a success by Seung Tak. He ended up remembering everything that happened while he was in a coma. Initially he played it off like he didn't remember and he was still the mean a-hole doctor but then revealed later to the VP during his recovery that he was going to eventually wake up and come for him. The bad doctor turned himself in and the VP & Se Jin's brother went to jail. Grandpa Tess bids farewell to the hospital and his granddaughter. He possesses the cleaning lady to have his final words with his granddaughter and gave her a chocolate cake and the granddaughter knew that it was her grandpa. Prof Cha returns back to work and Seung Tak will work along side with him so the bromance continues. Prof Cha and Se Jin move in together where they will live happily ever after.