Invitation is a song by Japanese composer and lyricist rerulili (Kouhei Sasaki) featuring vocalist lon. It was originally created as an original track for Sega's rhythm game CHUNITHM and crossed over into maimai during PiNK PLUS, arriving on June 30, 2016 as part of the early content-sharing initiative between the two arcade titles. The track is an energetic J-pop/rock number at 147 BPM. Its lyrics, written from a teenage perspective, channel frustration with school lectures, gossip, part-time jobs, and parental scolding before pivoting to an escapist fantasy, an invitation to a musical paradise where one can shed inhibitions and become their true self. The song's relatability as a coming-of-age anthem about finding freedom through music and games helped it resonate with the rhythm-game audience. In maimai, the MASTER chart (level 13, constant 13.0) was designed by the anonymous charter 某S氏, while the EXPERT chart (9+) was designed by rioN. The chart levels have been revised upward across multiple versions as maimai's difficulty ceiling expanded, the MASTER chart originally debuted at level 11 in PiNK PLUS before climbing to its current 13. The jacket artwork features the character Araba Ruko (荒場 流子), illustrated by しきみ (Shikimi), with the promotional video produced by 鑓田(alpha complex). A sequel track, RevolutionGame, later appeared in CHUNITHM AIR PLUS. A Vocaloid version of Invitation was also distributed during the CHUNITHM location test, and an extended version appears on rerulili's album Chuubyou Gekihatsu Boy (厨病激発ボーイ).