Recommendations

Second-Chance Romance After Forced Separation
Both dramas center on couples who fell in love in high school/college but were torn apart by external pressures, then reunite years later

Undercover Male Lead , strong female lead protect the ML ; she later discover her reality andher real parents and how they died

Both are revolving around traditional operas. In Kokuho it's kabuki, while in Sopyonje it's pansori.

Similar plot, there is some kind of spiritual things happening and there is a police officer, some cases and an adviser/consulter. High bromance/bl/love between them

While Brave Citizen is not necessarily revenge based, Ballerina is. However, the reason why I consider both movies to be similar is because of the action scenes and badass female leads. If you liked that aspect of Brave Citizen, definitely try Ballerina.

Both are revenge based. If you liked the action scenes in The Manipulated, you’d be more than happy to witness the ones in Mercy for None. The fighting scenes in it are just impeccable.

Ticket to Heaven reminded me of this lesser-known Korean short film. Very similar themes and dynamics (so far). Both lead actors did a great job showing religious guilt for being gay.

Undercover High School’s storyline is not mainly based on seeking revenge or beating up bullies. However, it’s still something that Teach You a Lesson fans would find very enjoyable as the protagonist of the drama is a cop as well and puts bullies in their place even when that’s not a part of his mission. He exposes the school he’s undercover at and also its principal(the antagonist), indirectly seeking revenge for his father. Moreover, actress Jin Ki Joo is a part of this drama as well!

Both are set in a scenario based on seeking revenge for other people. While Teach You a Lesson is solely related to schools, teachers, students and anything along the lines of that, Taxi Driver captures broader areas. Definitely try Taxi Driver if you want to watch a more inclusive version of Teach You a Lesson!

Pretty similar, imo. Both are predominantly revenge based. I believe the fighting scenes are quite alike as well. However, The Manipulated may be a little more on the extreme side. It’s still worth the try

same genre and is also BL and has a vampire love storyline which is why I think if you liked sweet blood you will like the Thai drama BL revamp.

same genre don't know what else to say but if you liked sweet blood you will for sure like my secret vamire

they are co-workers and rivals and at the same time, behind the doors, they have an affair in both show. And of course queer love story

Kamisama no Ekohiiki is a hidden gem. One side love story has similarities to Ticket to Heaven also, religious gay love (main love story also queer, there is even a lesbian love story), there is a priest character who tasted that kind love when he is young and rest is spoiler. Both show represents real life struggles of being queer

Fl somehow inflict damage to ML, in lie, it's indirectly
Both leads are cunning
Fl hidden identity
Revenge against parent