I'm looking for dramas where the lead changes himself in order to  get the girl. Like if he was rude or did a sketchy business but once meeting the female lead, he changes. some examples I've already seen are

Boys over flowers

Healer

The liar & his lover

Please help thank you! <3

Autums Concerto

Back to 1989

Im not a Robot

Shining Inheritance

Innocent Man

The Secret Life of my Secretary


The ML mistreats the FL because of a misunderstanding, but change after all misunderstandings are cleared:

Secret

Kleun Cheewit

Cinderella and the Four knights

Moon Lovers : Scarlet heart ryo tragic ending)

Go Go Squid

Kiss Me

Oh my ghostess

You're Beautiful I wouldn't say he changed his personality, he just started liking girl but treated everyone else the same as before

One of the best, and cutest stories I've ever seen about a ML who becomes a better man for the FL is Dr. Gang (2006) about a gangster who's on the run for the police, goes undercover in a hospital as a doctor, there he falls in love with a female physician.

The Kings2Heart -> He is a spoiled arrogant prince of South Korea and meet a very skilled military woman from North Korea 

Falling For Innocence -> After a heart surgery a really evil bastard starts to develop feelings for a woman the former owner of the heart used to love

Hotel King -> When her father dies a young woman return to the hotel her family owns to find who did this to her father. The new manager of the hotel seam to be involved...

Movie

Always -> a illegal underground fighter meets a blind girl and cannot help falling in love with her

  1. Dream high - lead female changes for the better

Scarlet Heart Ryeo - ML changed like the ML in BOF 

Radio Romance- ML started to show people how he really feels

Secret Garden- ML became more caring and stopped being rude 

1. Orange Marmalade 
 Main male lead stops needlessly hating vamps just for being vamps.
2. Memories of Alhambra
Main male lead had a bigger temper and lesser regard for the welfare of others at the beginning.

Usually it's more the situation that the ML changes because he met the FL, not so he can woo her. Typically he thinks he's perfect or at least content with his life.

Because This Is My First Life - the ML has been emotionally dead for some time, other than his attachment to his cat.  He only lets someone into his life because his mortgage payments are so high, and never intended his roommate to be a woman even if she did get along with the cat.

Hotelier

When one of the main leads falls in love with the manager of the hotel that he wanted to buy and then  resell, after many many episodes full of hate, pain, stubbornness and thoughts of a businessman, he decides to put aside his plan (he had been entrusted with that work by a partner and for him his work was the only priority) - - - [The character is much deeper than this, so I encourage you a lot to see the drama if you can. The internal processes of this character are very deep and well developed]