overall, this show is worth watching, even if on the side. i enjoyed it for the most part. it has an amazing cast, mature script, and a plot that is watchable enough. my favorite aspects of this show are the slow burn romance, the realistic conversations, the healing, it all felt very genuine. i didnt see it as too slow or boring initially, i somewhat enjoyed how they addressed coping with trauma and how they depicted the lives of 30-somethings. but this show does have its setbacks (which i dont think necessarily overpower the positive aspects of the show), which ill be discussing below.
GENRE
its genre, or lack of specified one, has to be the biggest issue. those that saw the romance/ drama tags were probably offput by the random scenes regarding murders and crime, and those that looked forward to the thriller and mystery tags were probably disappointed by how fleeting the scenes really were. this drama tried to be a jack of all trades, it took much on its plate and subsequently wasnt enough to satisfy anyone. if the director had chosen one genre to focus on, theres no doubt this wouldve been a fantastic drama. instead we are left with what feels like a mash up of two different shows entirely. in my opinion, this show wouldve worked best as a slice of life, considering the backstories of each character and how show chose to approach their growth.
INCONSISTENCY
this leads me to issues with consistency: the thriller/ mystery subplot took up a large portion of the beginning of the show, dwindled near the middle, and resurged near the end for the reveal. the show tried its best to blend scenes of opposing genres as best as they could, and i think they did a fairly good job- at least in the beginning- considering the challenges of shifting moods. but overall this show was a romance, with a subdued mystery shoved in to keep up with the current trends in kdramaland. they packed so much into one drama that it felt messy and inconsistent as each episode went on. there are other minor inconsistencies that i will mention at the end of this review.
TROPES
despite having a really mature feel within the issues of our characters and their relationships as well a genuine script, this show still managed to use EVERY cliche kdrama trope in existence. im talking childhood connections, unnecessary breakup, love triangles, lead with fatal illness, the stalker second lead, doppelganger/ twins, the shaman, forgotten first love, etc etc. they handled them okay, but it goes hand in hand with the overwhelming+ unnecessary amount of genres. this show had enough plot+ subplot to keep viewers entertained without relying on an over abundance of childish tropes. it cheapened the overall viewing experience, for me.
CHARACTERS
i liked the characters initially: the FL had a personality, and the ML wasnt a jerk. low standards, but its a refreshing change from many kdramas. their chemistry was alright, but i mostly liked how their relationship formed and how mature their conversations were. BUT i hate that midway and onward, most of the characters were only there to serve the FL/ML romantic arc. like gayoung was just there to make sure ML would rethink his stupid decisions even though character had so much depth and potential; she was depicted as mentally ill and s*icidal but it was only used in the beginning to serve shows purpose. similarly, cafe owner bff had family trauma and a past relationship issue which was only mentioned a few times, and we dont know anything about the brother at all. as for ian chase, they shouldve focused more on his internal struggle and ptsd, instead of turning his subplot into a murder mystery. the combined FL and ML friend groups during the camping trip were cute and i was hoping to see more intermingling and growth, but they only came together to discuss how to make FL and ML a couple. even the FLs storyline reverted to focusing on ML later in the show, even though she had unresolved trauma, a job, family dynamics, and so much more that couldve been built upon. MLs trauma wasnt unpacked at all, only briefly shown through flashbacks. all of these wouldve made great subplots for the drama, had it chosen to focus on slice of life instead of a mediocre romance and half baked mystery.

THE REVEAL
even after the reveal in ep 13, i was still confused. the scenes from 2003 were especially confusing. ian was the twin in the fake foster care, but why was chae jun the murderer? which twin forced the other? or was ian the murderer after all?? it just wasnt clear at all, no matter how many flashbacks and reveals they showed. by the end it was more clear, but it shouldnt have taken so long.

notice how all of shows problem come from doing too much and not enough all at once? if show had simply chosen one main genre to start with, this wouldve all been resolved.

here are some small details that bothered me:
1. the cinematography for the first episode was complex, and completely different from the rest of the show. i guess they were trying to make an impression but it made it hard to keep up, even though in retrospect the events that occurred were fairly simple.
2. i hated how the SML, chae jun, was even given a romance arc. he was creepy and stalker-esque since the beginning, following FL around from her place of work to her home even after she said no.
3. the actress for the FLs mom is only 15 years older than the actress for the FL. im not saying its impossible for her to play FLs mom, but she also LOOKS young, or at least too close in age to FL. it feels like they chose an "older" actress thats nicer to look at because she was getting so much screen time, and had a potential love story. in my opinion, they couldve easily hired someone visibly older to play FLs mom. attractive people arent the only ones that deserve to be portrayed on screen. think of iconic kdrama moms such as kim mikyung that couldve played this role well, despite not being "conventionally attractive".
4. FLs mom has a love interest thats mentioned many times in the beginning, and then disappears.
5.show kept shifting the villain between different characters, which is understandably part of the plot's progression but it makes it hard for viewers to have a deep hatred for the designated antagonist, as he shifted from the second male lead, to ian chase, to the woman who wanted her father dead, to the homeless guy etc and didnt give us enough time to just hate the villain.
6. ​i know that this is a kdrama so everything has to magically line up, but seriously? ian chase HAPPENS to stay at her hotel? the wedding in ep 13 HAPPENS to take place in her hotel?? is it the only hotel in seoul or what??