Legend says an evil Dark entity's soul, Gerard, was sealed by a Light entity, Lydia, in a stone governed by two swords. Sakura believed the legend was a myth until her childhood friend, Hideki, returns to their hometown. Her life overturns when she learns that she & other kids hold Lydia's elemental powers, with Hideki bearing a key item: The Light Sword. Reluctantly, they set out on a journey to understand their connection to the legend while uncovering secrets and revealing past wounds.