The first-ever theme song from "THE IDOLM@STER SideM"'s special project "M-Fes" is here! Continuing from 2025, "M-Fes 2026" is a special project in which the idols of 315 Production collaborate with a variety of companies. This CD features W, Shinsoku Ikkon, and C.FIRST. Alongside the all-member theme song, solo versions by each idol are also included. [Contents] 9 tracks in total: the "M-Fes 2026" theme song, its solo versions, and an Off Vocal version of the theme song [Format] Jacket featuring a newly drawn "M-Fes 2026" illustration with each idol's own expression. Vocal artists: W [Yusuke Aoi (CV: Yusei Kikuchi), Kyosuke Aoi (CV: Yoshitaka Yamaya)] / Shinsoku Ikkon [Suzaku Kurenai (CV: Takaaki Masuyama), Genbu Kurono (CV: Hisanari Fukamachi)] / C.FIRST [Shu Amamine (CV: Yuriku Ise), Momoto Hanazono (CV: Masaya Miyazaki), Eishin Mayumi (CV: Takeo Otsuka)]