光線チューニング (Kousen Tuning) is an original vocal track by Nayutalien (ナユタン星人), a producer whose bright, synth-driven electronic pop has made him a fixture in the Vocaloid and rhythm-game scenes. The song was created to commemorate the launch of SEGA's CHUNITHM STAR and arrived in maimai MURASAKi PLUS on the same day, August 24, 2017, as an event-course unlockable, later becoming generally available on October 3, 2017. This made it the first ChuuMai original song to debut simultaneously in both CHUNITHM and maimai since "Change Our MIRAI!" and cemented its role as a bridge title across SEGA's rhythm-game family. The track's vocals are handled by 000 (oreso), delivering a processed, energetic performance that complements the driving 190 BPM arrangement. Kousen Tuning's reach extended well beyond SEGA's arcades: it was later ported to Groove Coaster 4MAX and DJMAX II, bringing its total appearances to five games as of February 2023, tied with "No Limit RED Force" for the most cross-platform ports among GekiChuuMai (ゲキチュウマイ) vocal-original songs. In maimai, the song's charts have undergone level adjustments across multiple version updates, reflecting its enduring presence in the song list. The Master difficulty (level 13+, constant 13.7) was designed by はっぴー (Happy), while the Expert chart (level 11+, constant 11.6) was crafted by Moon Strix. Both charts belong to the STANDARD (pre-DX) category, with no Touch notes present in any difficulty.