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...