Scandal is a korean drama. The male lead is a cop and the female lead ended up working in a lawyers office.. It has romance part though not the mahor narrative factor of this drama. The story mostLy revolves around the male leads life, work and secret birth
missing you or I miss you where the ML is a cop or a detective and FL is a designer
Lovers in Prague an old drama where he is a cop and she is a diplomat. One of my fave kdramas ever.
Time between dog and wolf where the ML is not a cop, but he is an NIS agent, koreans equivanet to CIA. But he tasked to take down and investigate gang/triad organization.
While You were Sleeping, though he was not a cop, he was a prosecutor. Somewhat same type of work with trying to get bad guys. Plus they have a super adorable and awesome cop character in the drama.
There is another drama where the lead is a police but it was set during the japanese occupation of china, so being a cop actually means they are considered dogs of japanese empire, but he is actually an undercover freedom fighter. Same the girl. Its titled Bridal Mask
I also agree woth Hello Monster, though the female lead is also a cop. Same with the korean drama Posiedon, You are all surounded, HIT,
Black & White - taiwanese police drama that not only has 1 cool and handsome cop, but two handsome and coold cop in Vic Zhou and Mark Chao
there is another drama i wanna suggest, but its a different type of drama but probably the best among the ones i recommended. Anyway just check out Heartless City