The town of Tremorton New Jersey has a very special resident, a Robot Girl named XJ9 (or simply Jenny Wakeman) who was designed in order to protect the Earth by a female scientist, who more often than not would rather live a normal adolescent life. Having a robot at school makes your town stick out. It also attracts a lot of unwanted attention from invading space aliens, jealous mad scientists, and other bad guys out to take over the world.
Other notables in this world are Nora Wakeman, the scientist who designed the XJ series, and Jenny's neighbor Sheldon, the human alter ego of the super "robot" the Silver Shell. There is also a race of alien robots bent on conquering earth and liberating their enslaved brethren. Ruled by Queen Vexus, the Cluster are the primary concern of Jenny's Earth.