Can you guys recommend me any cute dramas where (preferably) a guy is already in love with a girl and he tries to win her heart but suddenly he starts falling for another girl and maybe that girl tries to help him getting the other girl? Something like what happened in the movie Our Times. Country doesn't really matter but I'd rather not have it high school based. Thank you ^^

Bring it on ghost
The day after we broke up- here the guy sorta likes another girl after breaking up with heroine..later realises the mistake.
Watashi ni Unmei no Koi Nante Arienaitte Omotteta: he is a mostly inexpert-with-women CEO who likes one of his employees, asks the help of a girl who develops those Date games. They become close friends, and eventually, they fall for each other.
Off the top of my head Full House, Delightful Girl Chun Hyang, Another Miss Oh, Coffee Prince, Goong, Cinderella and the Four Knights, Heart to heart, My Girlfriend is a Gumiho, Snow White, Which Star Are You From?, My Lovely  Girl
I really recommend Another Miss Oh, although it't not cute and fluffy and he is not currently trying to win the woman he is in love with back
Heartstrings (lots of fluff)
Second My Girlfriend is a Gumiho
Cinderella and the 4 Knights (also warm and fuzzy, although it wasn't one of my favorites)
Drunken to love You (Taiwanese)
Fated to Love You