When I See You Again (2015)

+ Leads meet as children and are friends/sweethearts
+ misunderstanding ensues and they separate
+ leads meet again in an antagonistic way as adults
+ ML originally wants to take revenge against FL but ends up falling for her all over again and chasing her first
+ rich but sensitive ML, poor but strong FL
+ similar kind of jealous childish ML character
+ both have love triangle around the FL iirc

One sided love in school meet up again years later....love story ensues

Childhood friendship, misunderstanding, meet again years later and love prevails! Love is Sweet is way better though

The story is very similar;
- Similar chemistry between Main leads
- Male lead want's to take revenge on the female lead.
- Female lead still thinks about the male lead who caused him harm
- Male lead hides his identity in order to carry out some form of revenge.