popcorn is an instrumental original composition by happy machine, first introduced in CHUNITHM STAR PLUS in April 2018 before being ported to maimai でらっくす PLUS in September 2020. The track sits in the ONGEKI & CHUNITHM crossover category, a recurring maimai genre that collects songs from SEGA's other rhythm game franchises. Running at a steady 130 BPM with no vocals, popcorn is a straightforward electronic instrumental whose bright, concise arrangement complements its namesake. The jacket illustration features Pendela (ペンデラ), a CHUNITHM-original character recognizable by her witch-like silhouette and pointed hat, giving the song a visual identity that ties it back to its source game. In maimai, popcorn's Master chart (level 13, constant 13.2) was designed by Techno Kitchen, while the Expert chart was handled by はっぴー, both established figures in the maimai charting roster. The song's Master difficulty has undergone level revisions across maimai updates, shifting between 12+ and 13 depending on the version, reflecting ongoing rebalancing of the game's higher-tier repertoire.