Key quickly becomes enamored with idol singer Miho Utsuse and wonders if becoming a singer will allow her to make the amount of friends needed for her to become human. But Miho carries a ominous secret: she is connected to Jinsaku Ajou, an old rival of Dr. Mima trying to make new a breakthrough in robotic weaponry. As Key works to become a real girl, Ajou sets a dangerous plan into action, and it turns out there's much more to Key than meets the eye.