オレンジの夏 (Orange Summer) holds a unique place in maimai history as the very first original song commissioned for the series. Composed by the duo Hiro and タクマロ, the track was created during the earliest phase of maimai's development, before the development team had even finalized the game's scoring and input systems. Over ten prototype songs were written and discarded before this track was ultimately selected to debut as maimai's inaugural original piece, with the working file name internally logged as "maimai-008." The song's core concept was "music that feels good to listen to" (聴いていて心地よい音楽), a deliberate creative choice rooted in the understanding that rhythm game players hear tracks dozens of times. The relaxed 132 BPM tempo, bright melody, and warm, nostalgic atmosphere, evoked by the title's imagery of an orange-tinted summer, were all crafted to stay enjoyable through repeated plays rather than wear thin. The result is a breezy, laid-back track that stands in contrast to the high-intensity originals that would follow in later maimai versions. The Expert and Master charts were designed by ニャイン (Nyain), and the Master chart's difficulty level has risen over the years as the game's overall difficulty curve evolved, settling at a 12.4 constant in the DX era.