Recommendations

A cop undercover for many years and he is thinking that this is the last job! This is identical, right down to the use of morse code and two opposing undercover (one good and one bad).

They obviously took the flashback and made an entire movie for the Japanese movie special from Internal Affairs II. The story is about a cop who has been undercover for over 10 years since finishing the Police Academy and only one person knows he is a cop.

Both movies have a taciturn lead whose armor gets stripped down by the girl.
Both movies are the story of two jaded people falling in love...

Though Cyrano Agency leans more on the romantic comedy side and Architecture 101 on the melodrama one, both deal with the bittersweetness of first love.

Both dramas deal with a couple getting married because of an arrangement and because the girl is head over heels for the guy. Though Wedding is more mature than than Sweet 18.

Wakamono Tachi bears a strong resemblance to Under One Roof to an astounding degree. There might be more siblings in Under One Roof, but those in Wakamono Tachi share the same issues as many of them (albeit mixed around). The eldest brother in each is a hard-working, lovable goofball who talks loud and fast. There's a lot of bickering at the table, a young sister having an affair with an older man at work, etc. But aside from these and other similarities, both are warm family dramas with a lot of heart and a good message. Plus, they each have "the cast of the decade," so to speak.

Both revolve around wandering martial artists who learn some powerful martial arts from some master and end up becoming renown. Both main characters dont rely solely on their martial arts but also on their cunning and careful planning. A Step Into the Past would be a casual recommendation for wuxia fans that have already seen all the better shows like Laughing in The Wind. Both are historicals but A Step Into the Past begins in "modern time".

Both are adaptations of Jin Young novels though they are different stories. Both are the best adaptations of their respective stories. If you liked one you'll probably like the other. First time I watched Demi Gods & Semi Devils I dropped it because from the first episode, I thought the martial arts was too over the top, exaggerated and fake/sloppy. But after giving it another go a couple months later, I realized it was pretty well done (or at least maybe in its later episodes). So I Highly recommend either for fans of wuxia series. Lots of good martial arts action.

Both dramas are based on chinese internet novels written by the same author, Gu Man.

It's basically the same drama, but the korean version. In both dramas the girls house is destroyed and she has to live with the family of the boy she likes, because her father and the boy's parents know eachother.

Very different films at first glance, though one reminds me of the other. Both of them are not mainstream, blue spring being very violent and kirishima messing with the story line a bit. What they have in common is the portrayal of young people being locked up in a neat and little world called high school and looking to the outside world, thinking, what the heck am I gonna do. What is it that I want to do. And does it even matter.
In addition, both have terrific soundtrack.

Both about couple whose on the same line of work and fought over. also romantic comedy

Unlikely love develops and though the girl is not pretending to be guy, she was just a little "unladylike". It was fun to watch and light to your heart.

Its theme on gangster, love, lies and hurt and "softees" of supposedly hard core men...

They have the same lead actress for one; and a lot of the music, filming & characters tend to remind me of this drama - they are both, sweet, romantic & fun :P