いっしそう電☆舞舞神拳！ (Isshisōden☆Maimai Shinken!) is the official theme song of maimai MURASAKi, composed by veteran rhythm-game creator satsuki ga tenkomori (さつき が てんこもり) and sung by YURiCa/花たん (Hanatan) at a brisk 185 BPM. Its title is a deliberate wordplay: いっしそう電 intentionally misspells 一子相伝 (isshisōden), a term for a secret martial-arts technique passed to a single heir, while 舞舞神拳 reads as "Maimai Divine Fist." The lyrics embrace the joke entirely, they narrate the player's own actions at the cabinet, calling out slide patterns ("12345のスライド, スライド"), rapid button sequences ("87654を連打, 連打"), and declaring with theatrical bravado that once you play, you automatically become a disciple. It is a song about playing maimai, written for maimai players, and delivered with a wink. The jacket art whimsically displays only "舞舞神拳," leaving the rest of the title to the imagination. Released on December 15, 2016, the track debuted as MURASAKi's first Challenge Track, available only in the challenge slot from launch through December 28 before entering the regular song pool. In Asian English versions of maimai, the song was retitled "How to be maimai sinken master!" with the artist listed as TENKOMORI feat. YURiCa/HANATAN, a localization that leans further into the mock-instructional tone of the lyrics. The EXPERT chart was designed by the anonymous 某S氏, while the MASTER chart (level 13+, constant 13.7) was handled by はっぴー (Happy), who packed it with 217 Slide notes, a high count that gives the chart a distinctive, flowing character atypical for its era.