Being marketed as a blend of romance-thriller, this is one of the rare dramas where the proportion is 90-95% thriller/mystery and 5-10% romance. The serial killer plot is the reason that grabs you to watch and finish this series, rather than its romance OTP aspects.
(It has no second leads unless you consider Yoon Young's parents' younger version as the second lead)
The storytelling is quite good; after quite a slow start, you will be hooked soon on who's the serial killer and their connection to our leads - in fact, family history and bonds are the strongest part of this series as it deep dives into our main character's generational trauma and past secrets. Layers are being unfolded quite cleverly, and for this reason, I keep a watch on the writer for his/her future works - quite promising for me. What didn't work for me was the directing - unlike other beanies, I'm not sold on the colorful 80s production design which I felt like belong more to series like Reply or Miss Granny, but not for thriller-ly ones such as this one ... also, the pacing is a tad to slooow in the beginning, which honestly this can benefit from about 2 episodes cut.
The best performer in this series are Yoon Young's mom & dad (the younger version) - both are pairs of promising rookies.
I also found issues with the ending, which is .... unsatisfactory, at best, about the identity of the serial killer itself, and how many deus ex machina it used to save our leads.
The drama can be quite violent by KBS standards, which is quite a low bar if you ask me; KBS dramas are usually not as violent as SBS, cable TVs (TVN-OCN), or the streaming platform ones (Netflix-Wavve & co, but it still feature some torture scenes in the context of historical 80s in Korea - a pretty much dark decade for the country.

Overall, I liked this series, it has its faults, but this series mostly works for me. The journey is more memorable overall than the destination.

I actually recommend this one for the murder mystery more than the romance. Although I actually did really like the romance, it's very subtle.

a little action, a little mystery, some investigation, a bit of romance, some family drama and a whole lot of heart. Maybe it because I've grown up on bollywood, but the mix of everything really appeals to me. almost reminiscent of old school k dramas. I really enjoyed this drama. But dont watch if you're particular about things like the science of time travel!