true my heart -Lovable mix- is an updated arrangement of the theme song from the adult visual novel Nursery Rhyme -ナーサリィ☆ライム-, produced by the ave;new music project. Composed and arranged by a.k.a.dRESS (the creative force behind ave;new) with lyrics co-written by vocalist Saori Sakura, the track first appeared on Sakura's debut album Lovable in 2007, the source of the "Lovable mix" subtitle. The song later received its own standalone single release, and the jacket art used in maimai matches the Lovable album's cover. The song entered the rhythm game scene via CHUNITHM AIR PLUS in July 2017, then arrived in maimai FiNALE in March 2019. Both the Expert (Level 10) and Master (Level 12) standard charts were designed by 某S氏 (Bou S shi), with the Master chart distinguished by a notably dense concentration of Slide notes, 87 out of 476 total notes, far exceeding the Slide count of the lower difficulties. The song's difficulty levels have been adjusted across multiple maimai DX version updates as the game's scoring landscape evolved. The full Japanese lyrics, available in-game, paint a heartfelt romantic narrative befitting its visual novel origins.