Recommendations

Similarities:
-The female leads are trying to deal with nasty gossip spread about them.
-Both male leads get into a relationship in order to protect the female leads from the rumors.. (Also how they eventually fall for the female leads)
-Both male and female leads technically meet at the airport.
-Both are centered around celebrities.
-Both are comedies.
Differences:
-In Her Private Life, the female lead is an obsessive fan of a local celebrity and is desperately trying to keep life her fan girl life private in order to keep her job. In Fluttering Warning, the main female lead is the celebrity trying to keep away from scandal in order to keep her job.
-In Fluttering Warning, the male lead gets into the relationship to avoid an arrange marriage and in Her Private Life the male lead gets into a relationship out of a misunderstanding.
Out of the two, just stick to Her Private Life but if the plot for Fluttering Warning sounds interesting, give it a shot!!

The stories are vastly different but I couldn't help but notice similarities between both dramas.
Similarities:
-The main female leads look and dress alike.
-The female leads are curious about the world but also shy (Heart to Heart's character has an actual social phobia and is WAY worse)
-The female leads knit and have a cleaning obsession.
-The romance between the male and female lead is VERY unusual and the people around them are always trying to break things off. (For the sake of the female lead)
Differences:
- Plot: Heart to Heart centers around a woman who has severe social phobia and slowly develops a relationship with her psychiatrist. Mary Stayed Out All Night is about a girl who's desperately trying to get out of an arrange marriage and gets into a fake marriage with a stranger she hits with her car...
- Romance:The psychiatrist falls and chases after the female lead first in Heart to Heart but Mary Stayed Out All Night is the other way around.
-Heart To Heart centers around the psychiatrist's job and the people they meet along the way whereas Mary Stayed Out All Night is focused on music and whether the female lead will escape the arrange marriage or not.
Both shows have a lot of charm to them and is great for a rainy day!!

From the synopsis it looked like both of them have the same underlying plot of a single mother who raised her kids abroad and came back home and meet the ml.

Similarities:
-The female leads are played by the same actress in both 3 Nen a Gumi and Mask Ward
-Both stories are centered around a hostage situation gone wrong.
-Both stories have a theme of revenge and justice.
-Both deal with controversial topics
Differences:
-3 Nen a Gumi takes place in a classroom, and Mask Ward takes place in a mental institution/nursing home.
- 3 Nen a Gumi is about the suicide of a classmate meanwhile Mask Ward deals with corruption inside the institution.
- 3 Nen A Gumi deals with the corruption in society whereas Mask Ward deals with political and medical corruption.
I recommend both the drama and film if you enjoy a good mystery and psychological thriller.

I found it very similar with when the camilia blooms because it has:
- the same actress
- the same scenario about "serial killer"
- close friends of the female lead get hurt because of her and get involved with serial killer acts

Same genre - Tomb Raiding, Adventurous & Discoveries/trap-solving of Wu Xie combined with the wu-xia style sects, focus on brotherhood/honor/etc

Both have jewellery as main thing, the FL dream is becoming a jewelry designer and hires her as an employee in M.R.M.B. and in N.T.M.Y. Gao Jie the FL has always dreamed of becoming a jewelry designer, so she packs up her bags to find work at a mining company in South America. She falls in love with Yu Zhi, the successor of Sheng Feng Jewelry. with alot of conspiring to take over the company by the ML stephmother.

Both dramas have wuxia (genre), martial arts, and fantasy. The characters also embark on an adventure with goal in mind to achieve.

In both dramas the protagonist enjoys daily excursions at different places, usually alone and mostly in silence.
They have similar vibes: a feel-good, soothing experience, depicting the magnificent scenery and natural wonders of nature.

Both shows have the males lead saving the female lead which become a crucial point for them to develop their relationship and bond.

It's technically the exact same story, just this time instead of getting the girl, the lead fumbles and gets the guy.

Both have the same genre of fantasy and romance. The characters also embark on an adventure. It is also set in supernatural settings.

The antagonists in these two dramas are both peacocks.
The male lead eventually becomes the emperor of the demon realm
Both are xianxia dramas.

Both are xianxia dramas in which the FL has a powerful identity that no one, including her, is aware of. Both FLs are very close to their only sibling (twin sister vs. younger brother) and they are students. Both MLs are not human and according to the rules of what they are aren't supposed to show emotions or aren't supposed to care about the FL. One of the leads has killed the other in their past lives. Both dramas have a similar feel.

Both are Republican Era mini dramas in which the detective ML and civilian FL team up to solve a series of strange mysteries.