Over a century ago, a calamitous event shattered the Moon, causing its debris to orbit Earth, weighing a mind-boggling 81 quintillion tons. Fortunately, Earth survived the tragedy, thanks to technological advancements, but the incident has long faded from memory. Haruka Amami auditions for the Idolmaster Project, harboring dreams of becoming a renowned singer, unaware that she's been selected to enroll in a covert school managed by the Mondenkind Agency. The establishment's objective is to control specialized robots called iDOLs, designed to intercept Moon fragments. However, the agency's motives and the iDOLs' true nature remain shrouded in mystery. As Haruka and her assigned iDOL, Imber, develop an inexplicable emotional connection, the situation grows increasingly intricate.