She and her perfect husband - both have older woman/younger man

Falling into your smile - both have the same ML

Gank Your Heart - both are cdramas that focus around e-sports and livestreaming

Exclusive Fairytale - both are cdramas (not aired yet)

Our Secret - both are high school to future transition

The Forbidden Marriage (2022)-- About romance between king and someone that is not traditional fit to be queen in the opinion of others.

Mr. Queen (2020)- MLs fight to maintain power as King and how both FLs end up impersonating the Queen of Joseon

Faith (2012) -In both dramas female leads who travels back in time and tries to survive in a country that they once knew as history.

JIN (2009)
Time-traveling and doctors that change the fate of the past.

The King: Eternal Monarch (2020)

Time travel current and historical period. Both strong main lead holding a high position. Trying to solve puzzle

Train (2020)
Both the dramas shows us parallel universe. 

Come and Hug Me - both have a serial killer