A town full of suspicious people, each protecting their own secret. Small mysteries connecting to a big mystery. Female lead is an outsider, trying to get to the bottom of things.

Same plot. Popular but snobby teacher (male lead) at a special training center fall in love with female lead who is one of the newer teachers.

Male Lead and Female Lead are close in their youth but unfortunate events occur to the ML, ruining his life and separating him from the FL. When they are adults, ML goes back to high school as a student where FL becomes one of his teachers.

Both series have birth mothers who are bad to their child, leading another woman to start caring for the child. However, the birth mothers stay in the picture and complicate the situation. Though the premise is similar, Mother is a lot darker and sometimes harder to watch. It includes physical child abuse, while Person Who Gives Happiness leans more towards child neglect/emotional abuse. Both shows will make you emotional as you watch. Person Who Gives Happiness is a longer drama, but well worth it if you stick to it. Mother is much shorter, but packs a lot into its few episodes.

Both are action romances. The male leads leave their countries and spend years in overseas drug cartels because someone close to them becomes high level drug lords (adoptive father in City Hunter and sworn brother in Age of Legends). They learn to fight and become overall badasses, and see pictures/hear stories about the female leads back in their home countries. When they finally come back to their own countries years later, they cross paths with female leads and romance ensues (after butting heads with each other at first). Both female leads are action girls. The female lead in City Hunter works in the secret service (president's bodyguard) while the female lead in Age of Heroes is a police officer. The main plot in both revolves around bringing powerful people to justice.

Angelo is a remake of the Korean version. Both have guys who go to find single mother and daughter with HIV in a remote village at the wish of their dead girlfriends. They grow as people etc etc

Plastic surgery causes memory loss for main character. Mystery and melodrama and romance ensue. Lots of secrets get revealed.

Dating agencies. Matchmakers falling in love. The Undateables is more comedic while Murphy's Law has more angst.

Playing matchmaker while falling in love with someone yourself. Both stories feature dating agencies, cute main couples, and fun side couples. The romantic development is faster in The Undateables while Cyrano is more of a slow burn. Cyrano features lots of celeb cameos.

Female lead is a reporter and male lead is a lawyer. There are supernatural elements which help with investigating cases (WYWS has main leads that can see the future while Meet Me has leads who share a time travel apartment). The romance moves relatively fast. The fate of the female lead is also a crucial mystery.