I would say this drama is by far the best korean drama I've watched.
I was hesitant to start it at first because it was a horror genre series. Not my typical Korean drama genre I opt for. But this drama changed my perception for horror genre. It was so mind-blowing. Not because it was scary or whatever, it's just pure good acting and the storyline.
Hard to believe they've managed to pull off a korean drama to be so good without any romance being involved. Yet, the chemistry between the main casts are so well portrayed and you can literally feel it. Still can't get over the bond between the casts and the soundtrack is so on-point. Brings out all the feels in you.
You tend feel to feel so much mixed emotions while watching this. I'd cried my eyes out for few of the episodes as well.
Overall, it's just a perfect drama with an A class plot. Some horror dramas tend to be illogical or fake sometimes but this was well-scripted with great acting by all the cast.
Go watch to all that are having second thoughts on whether to start the series or not. You'll never regret it.