Kouichi Minamoto is twenty and already B.A.B.E.L.'s fixer, which is why the agency hands him the three strongest espers in the country: ten-year-old Kaoru Akashi, Aoi Nogami and Shiho Sannomiya, the trio everyone calls the Children. Their powers outclass anything the government can field and their discipline does not, so Minamoto spends his days aiming them at rescue work instead of mischief. Espers are multiplying across Japan, and not all of them intend to be managed.