Usual second lead romance as main storyline

Hello! After watching dramas like A Gentleman's Dignity or Innocent Man I realised I was more interested by the second lead romance (both very cute) than by the main storyline so I was wondering if you knew of a drama that has a similar love story between a younger sister in love with one of her brother's friend and who finally gets through to him? For examples: Me Ahri and Yoon in A Gentleman's Dignity Cho Ko and Jae Gil in Innoncent Man The rookie actress and the director in the world they live in (they're not related outside from work but it has the same feeling to it) Thanks in advance!

Currently i can only rem moon chae yon- jung woo il pair in 'take care of young lady' They were supercute !!!! In fact the only scene i rem frm that drama is their sweet scene in ending episode, it mademy heart skip beat than anyother moment in the wholedrama so much that i replyed that part at least 10 times (ha ha laughing @ myself) Not sure whether it fits ur criteria though ??

Wild Romance Though I'm not sure if this can be of any help since it isn't about younger sister in love with one of her brother's friends but side romance story that was very cute. For me it was much more interesting than main romance.

Thanks for all your recs ! I'm going with Wild Romance, the others are way too long, they'll be on my PTW list till the vacations (otherwise I don't think I'm gonna be able to pass this year ;) )