Up! (Kep1er song)

On June 3, Wake One Entertainment announced Kep1er would be releasing their second extended play titled Doublast on June 20.^[1] On June 10, the track listing for Doublast was released with "Up!" announced as the lead single.^[2] Three days later, the highlight medley teaser video was released.^[3] The music video teaser was released on June 16 and 17.^[4][5]

"Up!" was written by Jinli (Full8loom), who also handled the composition and arrangement alongside Glory Face (Full8loom).^[6] Musically, the song was described as a combination of funk and house genres "harmonized by energetic vocals that elevate the refreshing atmosphere of summer to the fullest" with lyrics about "Kep1er journey through a dream island called happiness".^[7] "Up!" was composed in the key of F-sharp major, with a tempo of 124 beats per minute.^[8]

"Up!" debuted at number 14 on South Korea's Gaon Download Chart in the chart issue dated June 19–25, 2022.^[9] In Japan, the song debuted at number 27 on the Billboard Japan Japan Hot 100 in the chart issue dated June 29, 2022;^[10] on its component charts, it debuted at number 34 on the Top Download Songs,^[11] and number 46 on the Top Streaming Songs.^[12] The song ascended to number 37 on the Top Streaming Songs in the following week.^[13] On the Oricon Combined Singles Chart, the song debuted at number 37 in the chart issue dated July 4, 2022,^[14] and ascending to number 36 in the following week.^[15] In Singapore, the song debuted at number 29 on the RIAS Top Streaming Chart in the chart issue dated June 24–30, 2022.^[16] It also debuted at number 28 on the RIAS Top Regional Chart in the chart issue dated June 17–23, 2022,^[17] ascending to number nine in the following week.^[16] Globally, the song debuted at number 167 on the Billboard Global Excl. U.S. in the chart issue dated July 9, 2022.^[18]

Prior to the release of Doublast, Kep1er held a live showcase on the same date to introduce the extended play where they performed "Up!".^[19] They subsequently performed on four music programs: Mnet's M Countdown on June 23,^[20] KBS's Music Bank on June 24,^[21] MBC's Show! Music Core on June 25,^[22] and SBS's Inkigayo on June 26.^[23] On the second week, they performed three music programs: SBS MTV's The Show on June 28,^[24] MBC M's Show Champion on June 29,^[25] M Countdown on June 30,^[26] Music Bank on July 1, where they won first place,^[27] Show! Music Core on July 2,^[28] and Inkigayo on July 3.^[29]