μ's (pronounced muse) contains nine members: Honoka Kosaka (Emi Nitta), Eli Ayase (Yoshino Nanjo), Kotori Minami (Aya Uchida), Umi Sonoda (Suzuko Mimori), Rin Hoshizora (Riho Iida), Maki Nishikino (Pile), Nozomi Tojo (Aina Kusuda), Hanayo Koizumi (Yurika Kubo), and Nico Yazawa (Sora Tokui).

There are three mini idol units μ's is divided into: Printemps, BiBi, and Lily White. Printemps is composed of Kosaka, Minami and Koizumi; BiBi is composed of Ayase, Nishikino and Yazawa; and Lily White is composed of Sonoda, Hoshizora and Tojo.