22/7 (NANABUN NO NIJYUUNI)

One day, Miu Takigawa suddenly receives a letter notifying her that she has been chosen as a member of a brand-new project. Half in disbelief, she heads over to the location stated on the letter. There, she finds seven other girls summoned there in the same fashion. The girls behold a giant, top-secret facility. They stand in bewilderment as they are told: "You are going to debut for a major record label as an idol group." A new kind of idol, never-before-seen, is about to be born here… (Source: Aniplex of America) — Description from AniList community (anilist.co).