Recommendations

The set up like the the mean male lead, the kind helping and the cute idiot around the main girl is nearly the same

Both the drama and the movie are based on the same novel by the Chinese writer Hai Yan.

Same lead actor, lolool
About gaming; MMORPG, lololol
Goes into gaming world = CGI "gaming graphics"

Both protagonists are female mathematicians who uses their knowledge to solve problems. Hard Nut is more of a detective, which is a little more intense, while Suugaku Joshi Gakuen is a school drama.

Both dramas are about a couple with opposition to their marriage and side couples with similar situations. Both have a focus on familial relationships and the importance of money in marriage.

Both are thrillers, with a female lead, at the country side. Many secrets in both dramas.

Both take place in the late 1980s and both explore the romance between people who start off as friends. Back to 1989 includes time travel though and is a Taiwanese drama, not a Korean one.

In both the doctors have a complicated childhood. Their childhood influence in their medical careers and personal life.

PS:the surgeries and medical cases are amazing

Whilst watching this show, RH Plus kept coming to mind. The shows seem to have the same feel. Both shows contain supernatural elements but in RH Plus, there's vampires :D

Both dramas have these funny skits at the end/begging of each episode. Delightful girl Choon Hyang has historical skits while the main story is set in modern time and King is not easy has modern skits while having a historical setting for the main story.

the drama is similar in that the actress with the cop is full of baits

both are like a man who plays bodyguard, despite the resistance that falls in love with the main heroine

Both about past lives and how that affected the characters' current lives.

In both dramas, the leads remember their past.

Both have supernatural elements outside of the past life/future life trope.

Both have wonderful OSTs. CT is more artfully done while Legend is more quirky and fun.

Same writer and main lead, while the plots are completely different, they both have similar atmosphere..one sided crush, female lead getting bullied at work, gentle male lead..etc.

Both are mysteries, both female leads have a strong personality and both dramas are rom coms. The chemistry of the main characters is also brilliant.