Izumiko Suzuhara is a fifteen-year-old girl who has been raised primarily by her grandfather at the Tamakura Shrine, a secluded location deep within the forested Kumano region. Due to her parents' work, they are largely absent from her daily life, leaving her to grow up in an isolated environment that has significantly shaped her character. This sheltered upbringing means she has rarely left the shrine grounds aside from attending school, making the wider world unfamiliar and sometimes intimidating to her. Her physical appearance is typically described as plain or unassuming, with pale skin and long brown hair that she initially wears in two braids. She also wears a pair of red-framed glasses, given to her by her mother to help her avoid seeing unsettling spiritual phenomena that her eyes are naturally capable of perceiving.

Her personality is defined by a deep-seated shyness and introversion, a direct result of her secluded childhood. Izumiko is initially portrayed as hesitant, lacking confidence, and prone to keeping her opinions and desires to herself. However, beneath this timid exterior lies a quiet but persistent desire for independence and normalcy. She wishes to make her own decisions, to live a life similar to other girls her age, and to break free from the protective bubble that has surrounded her since birth. This inner desire manifests in small but significant acts of defiance, most notably when she decides to cut her own bangs short as a symbolic first step toward changing her life. This desire for a normal existence clashes directly with the extraordinary destiny that awaits her, as she harbors a deep fear of her own latent powers and the entity known as the Himegami that dwells within her.

Izumiko's central role in the story is defined by her identity as a yorishiro, a living vessel or container for a powerful and ancient Shinto goddess called the Himegami. This makes her a figure of immense interest and a target for various individuals and groups, including politicians, priests, and corporations, who seek to control or exploit her abilities. Upon entering Houjou Academy in Tokyo, a school that serves as a gathering place for young people with spiritual powers, she must navigate a new social environment while also coming to terms with her unique status. She learns that she is likely the final vessel for the Himegami, and this revelation places her at the center of a world of supernatural politics and power struggles. Her journey is one of transforming from a passive individual who is protected by others into a stronger, more self-assured person who can begin to make her own choices about her power and her future.

Key relationships are central to her development. The most significant of these is with Miyuki Sagara, her childhood acquaintance who is assigned to be her guardian. Initially, Miyuki resents this duty, viewing Izumiko as helpless and overly sheltered, and he treats her with coldness and scorn. However, as they face various supernatural dangers together, their relationship evolves from reluctant tolerance to mutual respect and, eventually, a deep and special bond. Izumiko's first true friend at her new school is her roommate, Mayura Souda, who also possesses special abilities and provides a sense of normalcy and support. She also develops connections with Mayura's brothers, Manatsu and the spirit of Masumi, and has a complex and wary relationship with the top student, Ichijou Takayanagi, who is initially an antagonist.

Throughout the story, Izumiko undergoes a gradual but significant transformation. She begins to shed her passive nature, becoming more confident and willing to express herself. She moves from a state of wanting to be normal and fearing her own power to a place where she begins to accept her role as the Himegami's vessel. Her motivations shift from simply trying to survive and hide her abilities to actively seeking to understand them and assert her own will. This journey of self-acceptance allows her to start reclaiming agency over her own life and destiny, culminating in a final acceptance of her identity as the Himegami reborn.

Izumiko possesses several notable supernatural abilities. From a young age, she has exhibited the unconscious power to disrupt and destroy electronic devices, including computers and cell phones, a phenomenon linked to her emotional state. She can also naturally perceive the spiritual realm, allowing her to see gods, ghosts, spirits, and other entities that are normally invisible to the human eye. As the vessel for the Himegami, she holds immense, often uncontrollable power that manifests in moments of high emotion. This includes generating powerful destructive forces, creating her own familiar spirit, and even transforming another person into an animal. She also learns to perform a spiritual dance called the Mai, which allows her to channel and direct her abilities with more conscious control, demonstrating a growing mastery over her inherited powers.