Miharu Ayase is Haruto Amakawa's childhood friend and first love from his Earth life, bound by a marriage promise made before his parents' divorce separated them for five years. Though they later entered the same high school, Miharu vanished mysteriously before reuniting with him. Her disappearance occurred when proximity to Satsuki Sumeragi and Kiku during a hero summoning ritual inadvertently transported her, Sendo Aki, and Masato Sendou to another world. Slave traders attempted to capture them upon arrival in a remote field until Rio, living as Haruto, intervened. Miharu possesses long, straight black hair reaching her waist, a gentle face, and stands 157 cm tall. Kind, modest, and calm, she avoids the spotlight but excels at cooking, impressing nobles like Liselotte Cretia. Generally reserved, she displays discomfort around men except Haruto, reflecting deep trust and affection rooted in their past. Initially hindered by language barriers in the new world, Miharu learned the common tongue through Haruto's teaching, achieving daily fluency. She subsequently trained in spirit arts within a spirit village, gaining basic proficiency. A significant development was forming a magical bond with Aishia, Haruto's contracted spirit. This bond enables Miharu to share magical energy and utilize diverse spirit techniques, enhancing her combat and support abilities. Miharu's emotional journey centers on unresolved feelings for Haruto. Meeting Rio (Haruto's reincarnation) sparked unexplained nostalgia, though she initially saw him as separate. Dreams mediated by Aishia and direct revelations gradually unveiled Rio's true identity. This realization solidified her love, prompting brave confessions even during confrontations involving Kiku or Takahisa Sendou. Her pivotal confession, conveyed through Aishia, transitioned their relationship to mutual acknowledgment. A critical revelation exposed Miharu's latent connection to ancient deities. During a battle against the earth hero Erika Sakuraba, Miharu and Haruto combined powers, awakening Aishia's memories. This unveiled Miharu as the reincarnation of the wise god Leana, who chose rebirth a millennium prior. Leana's consciousness resides within Miharu without merging, while Aishia embodies Leana's residual power and consciousness bound to Haruto. This divine link explains Miharu's innate affinity with Aishia and her potential for greater powers tied to her true identity. Throughout her development, Miharu evolved from passivity into actively pursuing her feelings and honing her abilities. Her deepened bond with Aishia facilitates access to advanced spirit techniques. Driven by enduring love and their childhood promise, she consistently commits to supporting Haruto. Her role expanded beyond personal relationships as she navigates the complexities of her reincarnated existence and its implications for the world's broader conflicts.