Mayura Sōda is a student at Hōjō Academy and becomes the roommate of Izumiko Suzuhara when Izumiko transfers to the school. She is one of triplets, alongside her brother Manatsu Sōda. The third triplet, Masumi Sōda, died at a young age but continues to exist as a powerful divine spirit whom Mayura and Manatsu can summon. Mayura is described as having neck-length brown hair with two separate bangs on each side, a red ribbon worn on the left side, and brown eyes. She is consistently one of the top-ranked students at the academy, often competing with Ichijō Takayanagi for the highest academic standing.

Her personality is gentle, charismatic, and outwardly cheerful, though she also possesses a strong will and a deep sense of responsibility. She is a loyal friend and an organized individual who values stability and order within her environment. Her motivations are closely tied to her family heritage. The Sōda family has a long lineage of shrine priestesses and a background connected to ninja traditions, and Mayura is deeply aware of her duties and the expectations placed upon her. She carries herself with pride in her family's spiritual legacy and is determined to uphold those traditions, even when it creates tension with more modern-minded peers.

Mayura's role in the story is primarily as a supporting presence and ally to Izumiko. As her roommate, she provides practical help and emotional grounding as Izumiko navigates the unfamiliar setting of Hōjō Academy and the awakening of her own spiritual powers. Mayura also serves as a representative of the established spiritual families that operate within the school's hidden social hierarchy, balancing her personal loyalty to her friends with the political and spiritual obligations of her family.

Her key relationships center on her two brothers. She frequently argues with Manatsu, but their bond is deep, and his well-being is her highest priority. The deceased Masumi remains a constant presence in her life as a spirit, and she summons him in critical moments to protect those she cares about or to confront supernatural threats. Her relationship with Izumiko grows from a simple roommate arrangement into a genuine friendship, with Mayura acting as a stabilizing influence while Izumiko comes into her own. She also interacts with other spiritual families such as the Takayanagi and Sagara lines, positioning her as a figure who understands the delicate balance of power among the various clans at the academy.

Throughout the series, Mayura undergoes subtle development. Initially presented as a model student who appears to have everything under control, she gradually reveals the inner weight of her family's expectations and the grief connected to her deceased brother. Her protective instincts toward Manatsu and her willingness to use her family's spiritual abilities show a more complex and vulnerable side beneath her composed surface. These experiences push her to reconcile her duty to her family with her personal wishes, deepening her character.

In terms of notable abilities, Mayura possesses strong spiritual power inherited from her family line. She can perceive and communicate with spirits and other supernatural entities. Her most significant ability is the capacity to summon Masumi as a divine spirit, who is extremely powerful and capable of devouring other spirits, as demonstrated during conflicts with Takayanagi's shikigami. This summoning requires the cooperation of both Mayura and Manatsu. Additionally, as a member of a shrine priestess lineage, Mayura is well-versed in the traditions, rituals, and spiritual knowledge passed down through her family, making her an informed participant in the supernatural events that unfold around her.