言ノ葉カルマ (Kotonoha Karma) is the debut track of rerulili's multi-chapter song cycle, the Kotonoha Project (言ノ葉Project), serving as the first episode of its first chapter. Written, composed, and arranged entirely by rerulili, widely recognized in the Vocaloid and utaite community for Nōsō Sakuretsu Girl (脳漿炸裂ガール), the song launched in maimai GreeN PLUS on May 15, 2014. In an unusual promotional approach, rerulili first uploaded the track to NicoNico Douga without disclosing its connection to maimai; the song quickly attracted numerous cover videos from utaite before its in-game origin was confirmed. The maimai version features a male-female duet between two of NicoNico's most prominent utaite, Soraru (そらる) and Lon (ろん), whose frequent collaborations over many years give the performance a polished, well-blended vocal chemistry. Musically, rerulili fuses a melodic J-pop sensibility with the rhythmic groove of black music and subtle accents of traditional Japanese instrumentation, producing an arrangement that complements lyrics about the dual nature of language, how a single word can wound or heal, bind or liberate. The song's jacket art visualizes this theme through stylized calligraphy and symbolic imagery. Over its lifespan in maimai, Kotonoha Karma has undergone several difficulty rebalancings across versions, reflecting the evolving standards of the game's chart scale. Nearly a decade after its original release, it received a Re:MASTER chart during the maimai DX BUDDiES era, designed by Jack, one of two note designers for this song alongside mai-Star, who authored the MASTER chart. The song also appears in SEGA's CHUNITHM series, where it has received multiple chart additions including a WORLD'S END and later an ULTIMA chart.