未来(ソラ)の歌 (Sora no Uta, "Song of the Future") is an insert song from POP IN Q (ポッピンQ), a theatrical anime produced by TOEI Animation to celebrate the studio's 60th anniversary. The song was brought to maimai during the MURASAKi PLUS era as part of a limited collaboration between SEGA, itself a co-producer of the film, and the POP IN Q production committee. Performed by Questy, a seven-member idol unit formed specifically for the POP IN Q project through a joint venture between avex, EXPG (Exile Professional Gym), and TOEI, the track delivers an energetic, bright pop sound at 153 BPM that mirrors the film's themes of perseverance and youthful optimism. Questy disbanded on July 25, 2017, barely seven months after the film's December 2016 release, making this maimai appearance one of the few lasting recordings of the group's work. The song remained in the maimai arcade lineup for roughly 400 days before its removal on December 13, 2018. Its chart set, built on the pre-DX STANDARD format without Touch notes, features a Level 8 Expert chart by はっぴー (Happy) and a Level 11 Master chart by ぴちネコ (Pichineko), both of which showcase the era's slide-heavy pattern design typical of the MURASAKi generation.