Rune is Yamato's friend and classmate. He acts collectedly, and often shows concern for Yamato. During the Heian era, he was originally a young noblewoman, Lady Gekko, who held romantic feelings toward the bandit Yamato. Reborn as a man in the present, however he still holds hidden feelings for his friend. Because of this, along with Yamato's infatuation with Makoto Sayama, Rune's deep-seated envy causes him to become the new master of the dôji Jealousy (Character) and to oppose Yamato.