The Smile Has Left Your Eyes (2018)

* both give the same feeling somehow
* both females are shiny and hardworking
*both males are poor and do a lot of part-time jobs
* there's a sad connection between them in the past
*both male leads are Orphan and they lived in a church
* both male leads attempted suicide

- Both have a tragic end.
- In both drama leads knew each other from there childhood and one of them didn't remember it.
- Both drama have heavy atmosphere
- In TSHLYE leads are deeply in love and we see it, while in KI it's supposed (I think) but we never actually see any romantic moments

Both male leads are intelligent, capable, and have a tragic, mysterious past haunting them. They are devoted to unraveling this mystery. Both have been wronged by the female lead's male guardian and have similar confrontation scenes with him. Both female leads are warm and make the male lead believe there can be something good in his life. (Spoiler: W has a happy ending; The Smile Has Left Your Eyes does not.)

One thing that kept me watching both dramas are Male lead character. If you're looking for same kind of male lead character then both the drama has one. Both gives similar "no fucks given vibe"!!

If you enjoy dark twisted romance dramas then this is the drama for you, both have antiheroes as leads, lots of twists and turns, BUT Byakuyako is definitely darker since the female lead is the real villain, in the smile has left your eyes the male lead is the twisted one, both are worth watching with good acting.

Both dramas gives similar vibes. Both are greatly directed, worth watching.
Both are melodrama/ thriller/mystery/tragedy type.

in Both dramas:
**Mystery/romance and even crime dramas
**Very similar MLs (it's main similarity of these dramas). mysterious and very charismatic, dark lonely antihero type ML, whos past is secret/mystery and also trauma for him. He is quite playboy, playing with girls feelings while not feeling himself anything, lying them, not regretting causing pain for girls who love him. He doesn't care much about anything, about material or even not material things, it's very hard to know what happens in his head or heart. It's very hard to make him feel anything, especially love.
**Though he is so closed type guy, from first view some may think he is very flirty and even funny, he is that way with FL too.
**FL is interested, intrigued and attracted by ML, wants to know more about him, support him... he opens up with her more then anyone (but still not so much, especially in "Piece")
**While drama develops, opens secret past of ML, overall his secrets and mysterious personality - is he so dark/guilty or not? is he killer or not?

Overall "Smile has left your eyes" is much (!) better and another level drama, "Piece" has this vibe and good details but isn't executed (or story isn't written enough good) as well... but these similarities is there and ML's really are very similar.
#So after Pieces it will be great to watch this great Kdrama (which has original Japanese version);
#After SHLYE you may enjoy with some similar vibes (but not expect same level drama).

Seo in guk is male lead in both.
ML is an antihero in both these drama.
Character of ML in both dramas have a melancholic vibe other than when they’re with FL. it’s only when ML is with FL that his personality becomes quirky and chirpy.
Both have FL who lost parents at a young age

The relationship between the leads is very understanding and mature. There’s some miscommunication as well, but not of the type that makes it unrealistic. Their situations make it plausible for them to react that way.