'Time Slip Dr. Jin (2012)' is the Korean version of the Japanese drama 'JIN' (2009) and 'JIN2' (2011).
Both deal with medical, history and time slip.

While the Korean version plays more with the romance by adding a male character as love rival, the Japanese version gives a more acceptable reasoning to why the time travelling happen.

Both have the same genre: romance and military - about love that grows under military situation.

Though 'King2Hearts' focuses more on politics & military, you can still feel the the strength of the love each character has. Meanwhile 'Descendants of the Sun' is more about the romance itself and also has the medical genre in it.

'King2Hearts' is about a South-Korean prince falling for a North-Korean soldier. Together they fight to keep their relationship while also trying to keep the peace between north and south.
In 'Descendants of the Sun' a female doctor struggles to have a relationship with a soldier from the special force.

While in 'Descendants of the Sun' we stillget comedy from time to time, it lessens in 'King2Hearts' as the situation becomes more serious.

Both are set around the same era.
In both the characters are touring europe, so you get to see great views of europe.

Both involve hidding their royal identity.
In 'Khun Chai Pawornruj' it's the female, while in 'Rattanawadee' it's the male.

Both are set around the same era.

In both the female lead is strong-minded, beautiful, well mannered and easy to fall in love to. But of course only the male lead started of by not liking her even hating her - always misunderstanding her and not able to see the true her. As feelings start to grow he keeps getting jealous seing her involved with other men.

Both have the supernatural element.
In both the male lead tries to change some decision they made in the past while havin an unsure relationship with the female lead.
Both are wonderful.

In both the male lead was accused by the female lead for raping/having sexual relationship her. And because both male and female want to win against each other they end up signing the marriage certificate. And so they continue bockering with each other.

Both have the same leading actor and actress.
In these dramas the female lead works as a celebrity.
In both the female and male lead didn't like each other at first and then start to develop feelings for each other. In both it's the male who realizes his feelings for her first.

Both are about the relationship of a spoiled well known actress with a man who endures her behaviour and slowly starts to have feelings for her.
Both are humorous.

In both the male-lead is forced into a marriage while having a relationship with another woman, who is an enemy of the female-lead.
The girlfriend try everything to get his attention and keep him away from his wife. The male hates his wife but doesn't like to see her with other men to the point of raping her. The male then slowly learns what's right and wrong.

Same case of male hurting female for revange and failing to see the female's true worth and regretting it by the end.

In 'Sanaeha Sunya Kaen' it's mostly the male himself that thinks bad of her, in 'Sanaeha Ngern Tra' the male is influenced by others saying bad things about her.

In both the lead girl is trying to solve a mystery while doing their job. In both the mystery is about the death of a woman.
In both there is a time when the first the lead girl suspects the lead male. Through out the serie the lead girl keeps on suspecting different person, but one by one are proven to be innocent and we keep on guessing the posibilities with her.

In both the male lead has the kind and gentle character, that women wish their husband would have.