a jerk/bully, becoming nice

I'm looking for more dramas where a character was a complete jerk then something happens that makes them try to be better.

Some examples that I watched and loved & definitelly recommend to others:

Chocolate

feel good to die

Bridal Mask

many thanks for considering my request.

• Skip a Beat 
• F4 Thailand: Boys Over Flowers/Hana Yori Dango/Meteor Garden 
• Promise Cinderella