In a distant era, humankind has regressed and now dwells in dispersed, minuscule communities. In addition to their day-to-day existence, individuals possess a mental prowess dubbed "Juryoku," which allows them to manifest their mental imagery. In the absence of contemporary technology, this aptitude has become a paramount source of energy. One day, Saki, a young maiden, and her fellow companions happen upon a diminutive archival robot on the fringes of their town. Its recordings disclose the antiquated history of humanity, including the genesis of Juryoku, which instigated a world war between psychics and non-psychics. Eventually, the psychics emerged victorious, leading to their oppressive power. After uncovering this confidential information, the grown-ups in their village deprive the youngsters of their Juryoku abilities and banish them. Fleeing to the sanctuary of a nearby forest, the troop comes across a colossal, hairless, two-legged mouse, referred to as a "Bakenezumi," and allies themselves with the animal in their continued conflict against a formidable adversary.