橙の幻想郷音頭 (Chen no Gensōkyō Ondo) is a Touhou Project arrangement by the long-running doujin circle 発熱巫女～ず (Hatsunetsumiko's), added to maimai PiNK on May 12, 2016. The track is a remix of 遠野幻想物語 (Tohno Gensō Monogatari), the stage 2 boss theme from 東方妖々夢 (Perfect Cherry Blossom), and takes its name and character motif from the stage's boss, Chen. True to its title, 音頭 (ondo) denotes a traditional Japanese folk dance song, the arrangement adopts a festive, call-and-response structure punctuated by cheerful interjections and a buoyant melody. The arrangement was a collaboration between circle members Tim Vegas and NAGI☆ (the latter later co-founded the sister circle FELT). Lead vocals were handled by capo, backed by an unusually large ensemble chorus featuring Youka, Chen-U, Maika, and ranko (of the circle Butaotome). The song originally appeared as a bonus track on Hatsunetsumiko's album eclipse I (2010), which also includes a karaoke version. In maimai, the MASTER chart (level 13.3) was designed by 某S氏, while the EXPERT chart (level 11.0) was created by はっぴー. The accompanying animation was produced by 東方活動写真館 (Touhou Kinema Kan), depicting Chen dancing in a hand-drawn style. The song later crossed over into SEGA's CHUNITHM series, starting with CHUNITHM PLUS in 2016.