Dramas where male lead falls for his best friends little sister?

Not best friend's little sister, but in Fight For My Way, ML falls for his best friend, who he considers like a sister or one of the guys, like he never saw her as a girl sort of thing before. 

Gentlemens Dignity. It’s not the main storyline though.

Maybe:

• Reply 1994 - they are like siblings in relationship, and one of the dilemna of their relationship was that ML is considered a son to FLs family
• Girls Generation 1979 - there is no sibling feelings, but the guy falls for the girl from the start, and later realizes she is the sister of his highschoolbestfriend
• Foxy Lady - ML older sisters Bestfriend is the FL. So its more FL falling for her bestfriends younger bro
• Hwarang - supporting couple, has guy fall for the girl who is sister to his childhood frenemy/rival
• Revenge Note - its the storyline of the second male lead. FL ends up with someone else. But still a cute fluffy and enjoyable drama
• Golden Pouch - ML and FL somehow becomes siblings at their adult age, then they fell for each other

✔️ She Was Pretty (best friends since childhood) 

✔️ Weightlifting Fairy (childhood friends)