Dramas that MC change (shy child to sucessfull woman)

Hi!

I'm trying to find a kind of drama.

One that at the past the m.c. was like ugly or something like that(like school time or child time) and "now" as an adult she is a sucefull person(in her job)...but then she find like a persom from her past(can be a bully or a friend, idc)

Is hard to find thing like that because appear usually dramas just about bullying(what I mean the school one) or some american movie or just some girls giving her life as an exemple. That makes so hard to find that kind of drama.

Plz give your recommendations.

Who are You: School 2015

Another miss oh : the Female Lead was frumpy and kinda self conscious in high school but when the drama starts she's grown into a well adjusted professional and has to work with her (one sided?) nemesis who was the popular girl bach in HS. The transformation in this drama is more realistic and less dramatic. There are flashbacks from her teenage years.