Miori Shiba is a supporting character in the anime Black Bullet. She serves as the student council president of Magata High School and is a close friend of the protagonist Rentaro Satomi. Her family runs a firearm manufacturing company, which provides sponsorship for Rentaro's activities as a civil security promoter. Miori is a teenage girl of average height with fair skin, blue eyes, and brown hair that is often styled upward in a ponytail with curled ends, giving her a traditional Japanese princess-like appearance. She is frequently seen wearing a kimono and carrying a folding fan.

Despite her gentle and somewhat helpless outward demeanor, Miori is a capable and resourceful fighter. She is proficient in the use of firearms, a skill likely stemming from her family's business, and she also wields her fan as a melee weapon in close-quarters combat. Her combat abilities make her a valuable ally in the dangerous world of Gastrea hunting.

Miori's primary motivation is her strong affection for Rentaro Satomi. This romantic interest places her in direct rivalry with Kisara Tendo, who also harbors feelings for Rentaro. The two girls frequently clash due to their shared crush, though Miori generally maintains a composed and polite facade. Her role in the story is that of a secondary supporter who provides material resources through her family's sponsorship and occasional combat assistance. She does not undergo significant personal development over the course of the narrative, remaining a steady presence as a friend and rival. Her loyalty to Rentaro and her willingness to fight alongside him define her place in the series.