Momo Minamoto is a high school girl in the city of Sorasaki. Interrupting her everyday life, the private intelligence agency "Tsukikage" scouts her to join their ranks. Tsukikage belongs to no man or country, and fights for justice and peace from the shadows. Consisting of only young women trained in mind and body and equipped with special tools and ability enhancers, they are in conflict with the criminal organization known as "Mouryou" currently spreading its influence in the city. Momo, under the tutelage of her seniors, finds herself participating in these battles to defend her friends and family.