My Dearest Song is a character solo track from SEGA's Irodorimidori (イロドリミドリ) multimedia project, sung by Marika Kouno as the voice of Shirona Tsukisuzu (月鈴 白奈). The composition and arrangement were handled by Tenmon, with lyrics by Daisuke Watanabe (credited as Lettuce Shichijou) and a music video directed by Hiromitsu Kawasaki (鑓田) of alpha complex. The song first appeared in CHUNITHM AIR on December 1, 2016, and was added to maimai MURASAKi PLUS roughly eleven months later on October 31, 2017. Lyrically, the song revolves around a cherished melody that persists across distance and time, the English title translates to "my most beloved song." The maimai version uses a shortened edit that removes one verse compared to the full-length version, which runs 2:42 and appears on Irodorimidori's second album 推薦 (Suisen). Within maimai, the track originally belonged to the ORIGINAL genre category; it was moved to オンゲキ＆CHUNITHM during the でらっくす PLUS update, reflecting the cross-franchise nature of the song's origin across SEGA's rhythm game lineup. The Expert chart, designed by LabiLabi, and the Master chart, designed by Jack, span a difficulty range that accommodates intermediate to advanced players, with the Master chart notable for its dense Tap note count of 610 and a Slide note count of 132, characteristic of Jack's charting style in this era.