Recommendations

Both dramas have a limited set of characters and the mystery plays out within an enclosed space. The themes are somewhat similar, exploring if a monster can be created in the right circumstances. White Christmas is more introspective and less violent as opposed to Strangers from Hell. Both are an example of brilliantly directed dramas, and anyone into thriller/mystery would appreciate them.

Ryu Sun Jae's sunbae and role model is Ahn Min Hyuk.
Both male leads are the sweetest, simpiest and total loser for their ladies

Both have a focus on the theme of prestigious schools, social hierarchy, and the impact one individual can have on a well-established system.

With this premise, this parallels with Bitch X Rich (2023) in terms of exploring power dynamics, secrets, and the clash between different social circles. Both are approached with a character who is a transferee that does not belong to the same high social class of students in the elite school as the transferee, defy the odds and going against the hierarchical system that already exists within the school.

Female leads are similar, 120 episodes or more, Male leads are similar, Second Female leads are similar

Why?
If you have already seen the series, you'll be just saying ... it's a cycle
For those that haven't ... we have the perfect cocktail:
one night stand
+
denial phase from one of the ML's
+
increase of dumbness + maniac girlfriend
=
?

It's like the movie, the difference FL instead of ML in the movie.

Han Se Gye is a top actress, also known as a troublemaker, with many rumors around her. To others, her life appears as a mystery, when in fact she is faced with a strange occurrence where she must change into a different body and new identity for one week a month. She encounters Seo Do Jae, a brilliant man who is an executive at an airline company. He seems to have it all: a perfect appearance, knowledge, and a good job; but he has a secret too. He suffers from Prosopagnosia, the inability to recognize faces. However, he manages to hide this from the world, every day he makes an effort to remember people by their personalities.

Both involve a commoner and a royal of opposite genders switching bodies and then being forced to navigate each other's lives, bickering and trying to swap back.

Both are historical mini dramas in which a royal lead swaps with a commoner/bandit lead, resulting in them having to navigate each other's lives all the while bickering.

Both dramas follow a plot where one of the leads have a life threatening illness. Both stories are centered around how the characters try to make most out of their remaining time left as they face medical hardships in the presence of the love they have for one another.

Both show the dynamic between rich and poor. The heirs has Kim Tan the arrogant male lead who's kinda mysterious, he has a poor gf aka the FL. Here we have a poor male lead with a secret and his rich female lead. Romance, high school, classism, bullying. Mix The Heirs and Elite and you got Hierarchy.

both have time travel romance with angst. both the female lead tries to change her past several times

Both are historical mini dramas with a FL who is a strong general entering into an arranged marriage with a weaker, rich ML.

Both time travel romances where one of the leads tries to save the other by trying to change the events in the past as a means to alter the future :)))))

Both FLs fall in love with a man who betrays them and causes their death in a fire. The FLs then find themselves back in time and resolve to change their fate, which leads to them growing close to the kind ML.

Both are short BLs in which the human lead discovers his cat has transformed into a human.
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