Recommendations

Both male leads are pushed into marriage they didn’t choose, to a female who is from the royal bloodline.
In both of the series the male lead is initially suspicious of the female lead.
Both males appear to have great fighting skills and are trying to uncover something.
Both Females leads are oblivious to the mystery the male is trying to solve.
Both Female leads are initially more committed and love first.
Both females leads are bubbly/cheerful while both male leads appear serious.
In both, the male lead attempts to push away the female lead for some reason.
Both series have the I chase you and then you chase me feel in the beginning.
Both appear to a mixture of comedy, romance, politics and drama.

Romance story of main leads from high school, not as much in first romance
Interview snips of the characters that tells you more about their personality
Both main FL loved by everyone, jealousy from other characters

Both movies have a cop undercover in a prison as the main character.
The Prison takes place almost fully in a prison while The Merciless skips around a lot.
The Merciless is definitely darker but it has a really good plot that makes you never know what is going to happen next.
Both are great movies.

There love was so real and the actor and actress killed their roles making it looked like real. If you are a sucker for real love watch this drama. Their kissed are so real.......

An amazing story of two game rivals coming together during times of Covid 19. They begin to really open themselves up and rivals turn into something better.

Both dramas are about fictional characters that become self aware. Both dramas are quirky and romantic.

similar story and premise only gender swaped about a popular woman idol marries a high school teacher and the kids don't like it.

Con artist
Crime
Badass characters
Con artist parents
Con since birth
Good plot line, doesn’t get boring

Like in " Tokyo Story", "Brothers and Sisters of the Toda Family" concerns itself with the failure of filial piety in an increasingly corrupt society.

Both dramas will show you what teenagers face in their life. The both female leads has a strict/overprotective mother which makes their life more tough.

Lots of twists and turns in both of these shows as they explore ethical concepts and the behaviors of those who are motivated by greed or envy.

Both involve warring families in the business world with high stakes. If you want to see a well-matched pair and a badass businesswoman, Ra Raerng Fai is good. The actors are also more mature/seasoned so the acting is excellent. So Wayree has younger stars and a very controversial start to the story.

#investigation Cold cases/missing people/death
Missing : The Other Side a little "brighter" and have more fantasy elements overall as compared to Signal.
Just watch it ;)

that surreal fantasy vibe,
ethereal male + Female-human
Male fighting off antagonist
Now that I saw the drama poster... It's kind of similar too XD

female lead of both shows fell into coma after an accident when they were young, woke up as an adult. + presence of male childhood friend as romance interest.