Best encapsulating the HYYH series’s existing themes of the beauty and recklessness of youth, “Run” is the title track of BTS’s 4th mini album, 화양연화 The Most Beautiful Moment In Life Pt.2.
The title was chosen to indicate evolution from past eras, as the group explained:

Part one explained how youth is tiring and difficult, and it also touched on how we feel like we’re always on edge. Part two will have a more adventurous and daring feel to it. That’s why our title song is ‘Run’."

It charted at #3 on Billboard and #8 on Gaon (South Korean) charts, exemplifying BTS’s initial hold over international markets even before they were as successful domestically.

RM also explained their intentions for the song at their press conference for their second part of “The Most Beautiful Moment In Life” concert series.

“We didn’t want to just blankly say ‘cheer up’ or ‘be strong.’ We really wanted to comfort people our way, by producing the music and writing the lyrics ourselves. We poured our heart and soul into this amazing song,”