Sailor Heart was destined to find the savior who would protect the world from the threat of monsters. One day, after saving a girl by chance, she intuitively sensed that the girl was the chosen savior. However, the monsters also learned of the savior's existence through the divination of the sorceress Aruru, and crossed dimensional barriers to launch their attack. Pursuing through a dimensional rift, Sailor Heart was ambushed by the monstrous knight Ergos, summoned by the dark mage Guraun, placing her in a life-threatening crisis. Yet, thanks to the savior's selfless intervention, Sailor Heart managed to regain her footing. In the end, expending immense energy, she successfully sent only the savior back to their original world.