Recommendations

It's a different storyline in many ways, but both involve solving a mystery at school. In the first it's a suicide case, in the other it's murder.

Like this Drama, Reflection of You is about two women who are engaged in a betrayal story.

The older woman has a rich family. Younger woman tries to annoy older woman and wants to destroy her life; because the older woman betrayed her husband with a man who was supposed to marry the younger woman.

many aspects are same but different story with an amazing plot twist. both leads in both shows are simply extraordinary doctors. Tho i think Doctor john is simply OP.

Both are really great action/crime dramas that also involve romance, though Cruel city hasn't romance tag, both dramas have romance as side story, but in K2 it was weak part, when romance in Cruel City was great, realistic, mature and hot, with amazing chemistry )))

both dramas have politics and complex relationships (when you don't know who is enemy or friend), very catchy plot and never boring/dragged. K2 has more high society's politic/corruption/business/secrets vibe, Cruel City - politic/corruption/mafia/undercover cops.

in both dramas ML is star of the show, but other characters are also 3D and really good. Plot and story lines are intense, reach and complex, with twist and turns, unpredictable and interesting till the end.
ML in both dramas is super badass, smart (Cruel City's ML is smarter) and physically strong with great fight skills; Also quite anti hero type, especially in Cruel City.

in both drama there is older SFL (practically equally FL, in K2 I would say she is more main than younger FL), who is very badass, strong woman and is interested in ML.

FL/love interest in Cruel City is much(!!!) better, she is strong badass girl.

K2 has more and better fight scenes (somehow even too much, like ML is superman but still great watch).

Cruel city is more dark!

Same school trope
Cute drama
The same type of feel when you see the Main couple
Secondary couple is also same irritating

The male and female leads meet in high school because their mothers are friends.
Both male leads are self centered players/jerks who are clueless about love; they have placed the female leads in the little sister zone; taken them for granted and have paid very little attention to what is going in their lives. In both dramas the audience knows early on that the female leads love and supports the male leads in their daily lives, while standing quietly in the backdrop and their shadow.

Similarity- only Ji Chang Wook!!! Fell for him. However Healer is his BEST! It's pure magic, a masterpiece indeed..

This series is inspired by the old movie "Whispering Corridors"

Source: Soompi
https://www.soompi.com/article/1497245wpp/watch-treasure-drops-spooky-teaser-for-horror-web-drama-thats-a-male-version-of-hit-film-series-whispering-corridors

This both series are both similar with love and jealousy and cute romance scenes..............................................................................................

The parent has memory lost, but they have up and down moment. The elderly still have passion and ambition. The son is in need to support the parent and walk a long side
Funny and hilarious

Both has an elderly person and a son, relationship
Very sweet movie/ film.
Older person life full of experience, always feel obligate to take care of the young one, but as their health and memory fate away, the younger person watch after them instead

Both movies about son and mother relationship
One is comedy the other one a little action thriller
Very sweet moment. Elderly mom

Both movie about mother and son relationship.
Both are Chinese movie
Very funny, awkward moment.
Son trying to take care of mom but mom always want to take care of the son

Both movie involved son and mother relationship.
It is very cute and funny indeed.
Mom has memory issue but stubborn as hell

these two dramas are similar because kiyoi and yu are both hot-tempered and stubborn. hira and gao shide also has a lot of similarities.