プリズム△▽リズム (Prism Rhythm) is the theme song of maimai でらっくす PRiSM, the version that launched in September 2024. The track reunites composer Shoichiro Hirata with vocalist Sana, the same duo behind Believe the Rainbow, the ending theme of the preceding FiNALE version. This marks the first time the artists behind one version's ending returned to compose its successor's opening theme, giving PRiSM a sense of musical continuity unusual for the series. The song was also the first original maimai composition available as a default launch track since BREaK! BREaK! BREaK! in Splash PLUS. Beyond its role as a version anthem, プリズム△▽リズム functions as a narrative teaser. Its lyrics reference six of the seven areas in the maimai でらっくす in-game universe, conspicuously omitting the Prism Area itself, and repeatedly call for a "secret key" and describe doors opening one after another. These are direct callbacks to the core loop of KALEIDXSCOPE, a hidden event that would be introduced later in PRiSM's lifecycle. The music video, illustrated by Masako Wada and directed by ツツミヒデアキ, deepens the mystery by introducing Ris, a character from the Prism Area making an early cameo, and showing a gate malfunction with a "LINK ERROR" message, a detail that would resurface at KALEIDXSCOPE's climax. An extended version of the track was first made available via the DiSC-PRiSM- goods campaign soundtrack before the standard-length version appeared in arcades.