Shiori Arisaka, a homeroom teacher at Mihama Academy, balances earnest dedication with a timid disposition. She sports medium-length brown hair and striking pink eyes, her unassuming presence frequently compared to a “nameless NPC” in a role-playing game. Prone to meticulous overchecking that borders on inefficiency, her cautious habits invite frequent admonishment from superiors. Beneath this ordinary facade lies a past steeped in trauma and sorrow.

Her history unfolds a harrowing childhood episode in which she intervened during her father’s abuse toward her mother, fatally stabbing him with a kitchen knife. Public backlash ostracized her family, though false narratives wrongfully accused her mother of the crime. To cope with guilt and societal alienation, Shiori mentally detached from her actions, shifting blame onto her mother. The incident left her tormented by recurring nightmares and an enduring dread of the outside world.

Upon joining Mihama Academy, she confronted a pivotal choice: depart or pledge herself permanently to the role, with disobedience risking fatal consequences. Despite uncertainty, she remained, discovering unexpected camaraderie among the academy’s misfits. Colleagues recognized her genuine efforts yet critiqued her persistent clumsiness and self-effacing demeanor. Through student interactions and introspection, she gradually confronted buried memories, unraveling the truth of her past.

Her evolution hinges on reconciling this trauma with her place at Mihama, where the academy transforms into a sanctuary—a stark contrast to her prior life’s isolation. This path traces her fragile shift from a fear-bound existence toward tentative stability, as she navigates purpose within the institution’s volatile ecosystem.