Nothing is perfect. This series has a lot of little flaws and plot holes here and there, but without a doubt still deserves the popularity and praise it has received up till now.
(warning: includes some specific scenes/details that may be spoiler to some)

I haven't watched very many kdramas so I'm not well versed in its world and cliches, but I have a very refined taste when it comes to what I consume. This series left such a wonderful aftertaste in my mouth that I can't find myself being satisfied with anything else for a long awhile. I started watching this randomly as it was on my bookmarks from a recommendation on some forum, but I never knew it would drastically awaken something deeply buried inside me: the young, hopeless romantic child in me.


CHARACTERS
In terms of character writing, I must say that the male lead has awaken the inner romantic child inside of me. It was my first time watching this actor and I couldn't help myself from staring at his beautiful, godly face. Holyshit he is HOT. I've never had a crush on an actor like this before, mind you. His face was perfect for his role, not to mention the character writing was obviously pandering to young romantics given the cliche nature of this "innocent but strong lone wolf falls in love for the first time" stereotype. But they handled that character really well in my opinion. It wasn't completely unrealistic and there were no extra gimmicks. He's just a very (highly) skilled antisocial man. The female lead character was also well-written to fit the male lead. She wasn't a damsel in distress that needed someone to save her, she was ambitious, enthusiastic, and fierce. I loved her upbeat, relatable personality with the dancing and singing and smiles. There are certain moments where she seems dumb with her choices but it wasn't anything irritating. To be honest I really loved the main characters writing. They seemed carefully crafted in fine detail with lots of thought put into. They were lovable to the point that you just want to meet them too. All the other characters weren't as memorable, but they weren't flat cardboard cutouts either. They did a fine job with the acting that you wouldn't really notice anything bad. You will be sucked into their world in no time.

ROMANCE
I was never interested in romance on kdrama until I watched this show. In fact, I skipped almost all the cheesy and borderline cringy scenes with main characters except for this one. The romance in this series was well-written, with natural depth and gradual development. I found myself getting interested and attached to their relationship, rooting for their happy ending. There were no unnecessary rivals, love triangles, misunderstandings. The love was pure and honest, they tell each other how they feel without beating around the bush or sappily dragging an incident all day long. Their chemistry would suck you in dry but will leave you wanting for more. For me, the way the developed feelings for each other was my favorite (the first few episodes when they met and interacted). Especially the scene where they were being hunted by a group of gangsters and she wanted to protect her junior. That was a very special scene to me out of everything this series had to offer (well, that scene AND the "spend the night under these white bedsheets" scene. Fuck, those two are just... chef's kiss.)

MYSTERY
I think this has the lowest points for me. The first few episodes were intriguing, but got confusing. There were hints scattered all around but I don't think all of them were picked back up again to be explained in the end. One example I could think of was Ji An's backstory. In the beginning it was apparent that she was traumatized after being abused and hit (which she ended up having broken ribs for), but it was never fully addressed in the end how it happened despite the trauma being a part of her while the story progressed (she gets seizures after seeing violence, and a little bit of flashback often appear). Who hit her? who abused her? because of the way the story was laid out, everyone would assume it was someone she knew, but I guess the writers wanted to leave it up to our own imagination. There are a few more instances like this, but overall it shouldn't be too much of an issue and you can just turn a blind eye on some of it.

ENDING
Not quite satisfying because they didn't show much of the characters lives afterwards (eg. what happened to the characters after being caught? The big brother? Ahjumma? Everyone else?) It felt a little rushed, but at least we were still given a lovely romantic scene at the end where the only thing the writers can assure us canonically is that they are now together and happy. That itself will be good enough.

MUSIC
I needed to address this so badly. The first episode hit me with that main soundtrack and I instantly fell in love. It was the first thing that made me want to keep watching because hot damn I can't get enough of that sound. I don't know what it is but I am in love with it. I was a little concerned about the way they overused it though. They used that main track for almost any scene - be it a funny, romantic, or suspenseful scene - often more than three times in one episode. I tend to enjoy my story through the music, because that's how I can reminisce and go back to particular moments in time with the characters. So now I don't know which scene I could associate that soundtrack to. I also need to specially mention their main romantic OST Eternal Love that plays usually at the end, during a romantic scene. The first time I heard it I thought of a band from my childhood that I used to listen to, and holyshit when I looked it up it WAS from them! Michael Learns To Rock! You have no idea how happy that made me feel, learning that one of my most precious favorite bands as a child was used in this precious, precious series. It made me love this even more. Those two were the most memorable ones to me, (maybe the cute little acoustic happy beat as well) but every other OST did its job very well.

OVERALL
I really enjoyed this story for the romance, which was the opposite of what I usually enjoy when watching series with concepts/mystery-driven plots. I've seen low-rated reviews and read them, and I think they have great valid points looking at this series in an objective manner (and perhaps it was simply not their preference). But for the most part, for everyone else who enjoyed this story, we were able to get past those little flaws and the series took us by the emotional level. Because of this series I wanted to draw Webtoon again. I wanted to write stories again. I even wanted to dedicate my own story heavily inspired by Healer as a character himself. His writing (the personality, looks) is just too... beautiful for me. It was all my fantasies in a full package tied neatly with a red ribbon and I never thought I'd find it. I never thought I'd the find the most fitting story for my taste in a korean drama.
Even as a writer myself, all the flaws and plot holes I noticed, I ignored happily. I can excuse whatever tiny bad details it has and give this series a shining, shimmering perfect score because of the way it made me feel.

I binged this show in two days, but I know it will stay in my heart for years to come.