Neptune, who has regained her memories from the heavenly realm, attempts to return to the heavenly realm with her sister Nepgear to save it. However, realizing that returning without collecting the necessary data for the reboot of the heavenly management system would be a waste of effort, Neptune and Nepgear, under the guidance of Headmaster Magikon, decide to start data collection as separate teams. Yet, the rampaging system relentlessly attacks Nepgear and her team. The fourth installment of "Neptune High School," featuring the sisters in action!