Recommendations

Both movie portrait a young person landed in countryside small village
Their life enrich by simple beautiful little town lifestyle
Beautiful cinematography, loving people

Both are about a young man with no purpose in life,lost soul, end up with learning valuable skill.
Both movies about wood.
Beautiful cinematography.
Slow, warm and sweet movie.
Peace, simple yet lovely

Both movies about young people were not happy in the city
They found peace and harmony in the village
They learned surviving skill, simple life style, and live rich and healthy daily life in small and lovely space

Both movies about a city bret didn’t have meaning in life went to village.
They are not only learned valuable skill, they village thought him many valuable meaning of life.
Sweet, warming movie

Both series focus on the lives of a group people very much passionate about engineering and maths. Start-up has programming as a central theme, here we have Maths and Calculus. Both have MLs who are geeks to begin with. The OSTs give a similar vibe as well!

> Both dramas focus on court ladies
> The friendships of the different court ladies, their relationships with their higher ups, emphasis on how they should serve and belong to the king, is shown in both dramas
> TRIVIA: The female lead Lee Se Young is actually the child version of the rival female in Jewel in the Palace! Her characters in both dramas are both court ladies that are very talented. In Jewel in the Palace, she can cook since she was 3 years and is very knowledgeable in the kitchen compared to others. In Red Sleeve, she's good at writing and poetry.

So the only reason I am recommending K2 for The Revenge is because of the bodyguard aspect and the actions. The OST even reminds me of K2, but the Revenge is a whole lot darker than the K2.

School bullying. A girl that gets help from someone who is a dropout and kinda seen as the "bad one" and a sort of revenge towards the bullies. Both dramas are very well done and have a surprising ending. The theme itself is quite similar as well.

Both are supernatural dramas with vampire/vampire-like creatures. The protagonist in both dramas transforms into a monster after a traumatic experience. They both also refuse to turn completely into a monster and stay partly human.

A sassy rich lead moves to the country side and falls in love with a friendly, poor person. That person makes the lead change themselves and grow. Both dramas show the rural life and the people living there act like one big family. The shows show the beauty of a simple life.

Both dramas are about a princess who, due to circumstances, have to grow up outside the palace. For sometime in her life, she doesn’t know she’s a princess. She eventually returned to her kingdom and was a very good asset in helping/saving her people. Princess Deokman in Queen Seon Deok uses her wits, Princess Pyeonggang also does it plus she also fights some battles for her people.

> Both are well-made romance historical melodramas made 10 years apart
> Has a strong female lead that saves her male lead a couple of times
> Amazing performances from both leads to the supporting casts, and even a senior actor with a prominent role (Suyang in Princess Man and King Yeongjo in Red Sleeve)
> There are a lot of other historical romance melodramas (you can see from the other recommendations here), but these two dramas are both well made, received high ratings, and great reviews in Korea and abroad. Princess Man won best director and was nominated for other awards for Baeksang years ago, there’s a high chance the same will happen for Red Sleeve.
> Both female leads were called historical drama queens after their respective dramas aired
> The leads in both dramas received top excellence awards and best couple awards in their dramas' respective stations at the year end awards for their performances.

FM is crazy about ML
ML acts like he doesn't like her back
ML is smarter than her
SML is athletic and popular

both are school dramas that follow their friendships and are low stakes

these dramas both have similar themes to each other
trauma, family and friendship to name the main points
both balance the heaviness of the subject matter with breaks of light-heartedness (more so in IOTNBO) and humour.

Similar vibes. Both romances are between a prince and someone who works in the palace so its a similar dynamic there and comes with similar conflicts.