My First Phone is an original composition by cubesato (the alias of Satoshi Yoshitake), first introduced in Sega's CHUNITHM arcade rhythm game. The track crossed into maimai with the MiLK PLUS update on December 4, 2018, and later into オンゲキ SUMMER PLUS, becoming one of the relatively few songs to appear across all three of Sega's contemporary rhythm-game titles. Built around a gentle 114 BPM pop arrangement with no lyrics, the song evokes the simple, mildly nostalgic experience of handling a first mobile phone, a theme reflected directly in its chart design. The jacket illustration features the character Magical Star☆Lily (マジカルスター☆リリィ), drawn by artist のん (Non), with a music video by murAta Yuzi. This collaborative package gives the song a cheerful, storybook visual identity that complements its lighthearted subject matter. In maimai, My First Phone is best remembered for its MASTER chart, designed by 譜面-100号 (Fumen -100 gou). Out of 532 total notes, only 2 are BREAK notes, placed at the very beginning and very end of the chart. This is a deliberate gimmick carried over from the original CHUNITHM chart, where ExTap notes, the CHUNITHM equivalent of BREAK notes, appear only at the start and conclusion of the song, mimicking the moment a phone call connects and disconnects. The maimai version faithfully reproduces this concept, making the MASTER chart one of the most distinctive novelty charts in the game's library. The EXPERT chart, designed by Jack, offers a more conventional 12+ experience with 458 notes and a steady stream of slides and holds.