Description
Mirai Kuriyama is a first-year high school student and Literature Club member, identifiable by her peach-colored bob-cut hair, golden eyes, and constant thick-rimmed red spectacles. She frequently exclaims "How unpleasant!" when agitated. Mirai hails from a bloodline of Spirit World Warriors, inheriting the heretical power to shape her own blood into weapons or corrosive sprays. Activating this ability requires creating a self-inflicted wound on her palm (anime) or forearm (light novels), usually hidden under her cardigan and sealed by a golden ring on her pinky finger. Overuse leads to severe anemia.

Orphaned and ostracized due to her powers, she was adopted by the Inami family but remained isolated until befriending sisters Yui and Sakura Inami. Mirai was forced to kill Yui when a Hollow Shadow possessed her, an act that traumatized Mirai and ignited Sakura's desire for vengeance. This guilt manifested as a debilitating fear of confronting youmu, preventing her from earning income as a Spirit World Warrior. Her resulting financial struggles and hobby of blogging about bonsai trees often drew ridicule.

Her path shifted upon encountering Akihito Kanbara, an immortal half-youmu she initially attacked, mistaking him for a target. With his encouragement, she conquered her fears to defeat her first youmu. Their bond strengthened as Akihito supported her through conflicts, including battles against the Hollow Shadow where Mirai shielded Akihito from possession, and later reconciled with Sakura after defending her in combat. Following these events, Mirai's Spirit World Warrior license was revoked for disobedience, leading her to take part-time work arranged by Akihito. She eventually moved in with Sakura as roommates.

During the Calm phenomenon, Mirai discovered her original mission in Nagatsuki City was to eliminate the powerful youmu "Beyond the Boundary" residing within Akihito. Choosing to save him due to her romantic feelings, she extracted the youmu at the cost of her own life, dissolving into nothingness after confessing her love. Akihito later entered a pocket dimension to assist her spirit in defeating Beyond the Boundary. One year after her sacrifice, Mirai reappeared alive but with complete amnesia regarding her blood powers, Akihito, and the events surrounding Beyond the Boundary. She resumed a normal life as Sakura's classmate and roommate, creating scrapbooks of "nice things" and participating in school activities like tennis tryouts, though she encountered a mysterious shadow hinting at potential supernatural remnants.

In the spin-off "Idol Saiban!," Mirai appears as a super-deformed chibi idol judge in a courtroom setting, wearing idol-style attire under a black court dress. She retains her signature glasses and anxious personality, frequently panicking during proceedings and uttering her characteristic phrase about unpleasantness. She often scolds Sakura Inami for showing minimal interest in the trials.