 The duo officially started their promotions for the song with a performance of "B.U.T" on the popular Japanese music television program "Music Station" on September 16, and the song's full PV was released on September 19.Tohoshinki officially released "B.U.T" and "Back to Tomorrow" on September 21 via online retailers.On October 2, Tohoshinki performed the song on Nippon TV's "Music Lovers".