The "Heian Chapter" is set in the middle of the Heian period, where the people of the capital of Kyoto are in deep agony, focusing their last hopes on the retrieval of the five magatama that represent the five elements (Metal, Wood, Water, Fire and Earth). Legend has it that when the magatama are laid together, their circle of Affinity will save the capital from suffering and whoever places the last stone is to become the emperor.
