MC trying to change

Lee Yeongja out of Hello Counsellor she is trying to lose weight at the moment and also Jae Suk  FROM rUNNING mAN found it hard for years to get recognised befroe he found a niche mc'ing on variety shows...dont know if this is what you are talking about but when I saw the word MC I thought this might be helpful

I can't think of any dramas that deal with weigh loss. It's quite hard to make one if you think of it too.

here are some dramas with other changes
''Nobuta Wo Produce''
it's basically 3 different types of people together;
1st - the mellow girl who is extremely shy and is bullied
2nd- the popular dude who is afraid to lose his popularity, so doesn't want to be seen in public with the other 2
3rd - the goofy careless dude who was the one who forced the friendship along the 3 in the first place, mainly to help the girl.
I think you can already guess what the changes are gonna be

''Missing You''
The first few episodes are when the main couple is younger. After an incident happened and they fast forward in time you can really see the male mc wants to change

''Piece''
The girl usually didn't care about anyone but herself, but after being requested to find the ex-boyfriend of a classmate she decides to accept the task and change herself along the way. I must say I really enjoyed this drama. The scenes were pretty, the characters interesting. I really wanted to keep watching. Though if you're the type that really wants a good written story, this isn't the one.

''Pin to Kona''
you got 2 male leads who both perform the same type of dance. The only difference is; 1 is the son of someone famous, who just does it because he has to.The other is a ''nobody'' who works hard to get at the top but will never make a chance without the right connections. My memory of it is a bit vague, but the rich kid was going to actually try and be more serious or something along those lines. It's basically the skill thing, along with attitude.

''Asuko March''
a girly girl who wanted to go to some all girl high school ends up failing her exam by accidently skipping 1 box causing her answers to all shove one place.
The only place left to go for her is a technical school with including her only 2 girls. The other girl only got in to flirt with guys and is basically a bitch so she only has the guys left. At first she was being mean, wanted to quit the school and whined about the stuff she had to repair. But along the way she changes and becomes friends with the guys and changes into more of a tomboy.

Leh Nangfah- I don't know if it's exactly what you're looking for because her attitude change isn't really her own doing, she's forced into it because she's cursed. But it does take a long time and a lot of self reflection for her to be willing to change.

Yehey! Thank you so much for adding some descriptions :-D Don't worry, don't focus on weight loss, just change in general hehe. Each of your recs were on point, it was pretty amazing haha. I'll try 20 mins for each drama / movie. Oh, and I'm actually trying to avoid "makeover" kind of change, especially if it is one time big time change - like he/she changed in less than 24hrs :))

Oh, & Thank you, thank you, thank you!