0+1=1 (I Promise You) is the second extended play by South Korean boy group Wanna One, a project group created through the 2017 Mnet survival show, Produce 101 Season 2, composed of eleven trainees from different entertainment companies that will promote for 18 months under YMC Entertainment.

[1][2][3] On February 26, Wanna One announced the release date of the special theme track and their second mini-album, titled 0+1=1 (I Promise You).

[6] "Boomerang" is an electro trap song that talks about one's heart reaching out to a significant other and returning after making a connection.

[7][8] Wanna One held a comeback show on March 19, which was broadcast live on Mnet.

[9][10] On March 5, it was announced that the number of pre-orders for the album has surpassed 700,000 copies, breaking the previous record set by the group.