context : - this is one of IU's important song bcs : (1)this is self composed - self written (2)different direction from her other songs (Good Day - You and I - Every End of The Day- The Red Shoes all is orchestral pop , well .... The Red Shoes got some jazz/ swing too) -Friday is one of iu's legendary song, it stays in top100 chart until mid 2015; and will have a slightly rise in chart every Friday. -Friday released in Dec 2013, but its still climb into top10 digital song yearly chart in end of 2014 ... and still in #70 in yearly chart 2015 - you dont realize, but that guy is the same as guy in The Red Shoes and My Mister (Jang Ki Yong) -Jang Yi Jeong is that "EL CAPITXN" guy in Eight song credit. Also he is now Big Hit producer....
I don't know if you noticed, but the dude that was in the black that was biting her finger is the dude from My Mister that was the loan shark's son. I watched the show before I heard this song so it's jarring to see the dude go from beating her ass too being lovey dovey with her. And jazzy IU is the best IU.
Lol your interpretation on the mv always got me :)). Kinda make sense that the friend-zoned guy wanting to warn her, coz that boyfriend guy apparently a loan shark and will beat her up for not paying her debt in few years from this 😅