Recommendations

Both main cast are under cover. They both have inner struggle. Putting their life in tremendous danger.

Both are about the undercover cop. They sacrify their family and love life for the country and for the job. They involve in dangerous mission and duty.

Just an undercover cop film. The undercover cop know how dangerous their job is but couldn’t get out

While quite different story and vibe wise, episode 4 of One Night Morning tackles a relationship with a FL with a stutter and the perceived lack of control and misunderstandings that the stutter and social fear may have inspired with the ML (who tends to give off a very intimidating/cold delinquent-like vibe to others). These elements remind of the two male leads in My Beautiful Man.

Both of these productions have a man-vs-self plot conflict as the main character is forced to analyze where they fit into their everyday life and relationships. There's also a prominent focus on intimacy in Between Complete and Incomplete that is seen in a few episodes of One Night Morning. The main character of Between Complete and Incomplete also reminds of the ML in episodes 2 and 7 of One Night Morning.

Both of these Japanese episodic anthology dramas center around a simple dish that has significant meaning to the central character of the episode. The episodes also feature characters coming to terms with an aspect of themselves or their relationships, and how quickly that can change in your everyday life.

Both of these episodic anthology stories center around a one-night interaction and food symbolism to convey life lessons. While very different in composition, the visuals of both dramas greatly contribute to the vibe and tone of the story.

Both of these productions feature short stories centered around a main character undergoing some sort of character crisis. While not necessarily grand in scale, these story conflicts are key to the leads' opinions of themselves and their relationships.

Both productions also feature prominent and reoccurring color symbolism and other metaphoric elements. They also both use non-literal intermissions where we see the main character in a setting effectively crying out for help.

ML and FL are a bickering duo in the law field and settle cases together. The dramas show cases episodically; a new case every episode. Leads are at each other's throats some times, but at the same time also have out-of-this-world level chemistry. FL in May it Please the Court was demoted to a less-reputable office, while in Ishiko to Haneo ML is sent to a less-known office and in both dramas they are paired with a very unlikely partner who they don't get along with at first. Both dramas are very comedic, heartwarming at times, thrilling at times, and all-in-all give good feels. Happy watching! ^^

Both female leads are idols and have a secret identity. In Sabu Doru, the female lead is actually 38 years old. In Mask, the female lead isn't what is considered "pretty" in korean standards.

the common thing is both have autistic fls. the movies plot is very different though the action scenes are really intense nd real no doubles were used while filming them its a bit mature type film not for everyone people who like martial arts nd stuff will love it

Something to check out if you like the prison arc from INSIDER.

Both follow MLs who are put into prison. Whilst the ML from INSIDER is innocent. the ML in ONE ORDINARY DAY has been arrested for something he doesn't remember. Both MLs are trying to find out the truth and both of them get close to the top dogs of the prison and they look out for them throughout both dramas (kind of...)

even though the genre is totally different
the vibe is same
sweet and bubbly FL
reserved ML
childhood buddies
short length series

If you were really into the card playing of INSIDER, you might also enjoy KAKEGURUI for the same reason.

KAKEGURUI follows a bunch of rich high schoolers who spend all their time conning each other in different types of traditional games. It's almost similar to a prison (quite like the one in INSIDER) where certain characters are treated horribly and second-class citizens and have to do horrible things. It also has its comedic moments, since the FL is a new student who is able to outsmart all the con artists like the ML was able to do in INSIDER.

Similar story of a female lead working in a male dominant environment with a cheating husband -- depicts the scandalous scandals of the nation's top law-abiding aristocrats dreaming of hereditary succession.