The song was pre-released digitally on June 12, 2019, and the CD single was later released on July 24 by Warner Music Japan.

[9][10][11] "Breakthrough" was composed by Jan Baars, Rajan Muse, and Ronnie Icon, with lyrics written by Yu Shimoji.

[12] Tamar Herman, writing for Billboard, said the song is "meant to evoke the feelings of a cool summer night" and "offers up a dramatic, brassier electro-pop sound that puts the nonet's silky smooth vocals front and center".

[1] The music video for the song was directed by Naive Creative Production and was released on June 11, 2019, on YouTube.

[19] It topped the Billboard Japan Hot 100 with 288,502 copies sold, 3,451 downloads, and 2,213,588 streams recorded from July 22–28, 2019.