Atsushi Kitamoto sports short brown hair and brown eyes, standing slightly taller than his classmate Takashi Natsume. He wears the standard school uniform of a white collared shirt and grey pants, switching to long coats and scarves in winter. As a first-year high school student attending the same school as Natsume, Kitamoto forms one of Natsume's earliest human friendships alongside Satoru Nishimura. This bond develops despite Natsume's initial wariness, rooted in hiding his ability to see yokai. Kitamoto and Nishimura frequently gather with Natsume as a trio, though they interact more regularly with each other than with Natsume. Kitamoto displays a sensible and rational nature. After his father fell ill the previous year, he decided to pursue a career as a public servant to support his family. This responsibility manifests in caring for his father, like adjusting his blankets, and managing his younger sister Mana Kitamoto, a middle schooler one to three years his junior. He discourages Mana from waking their father or buying doughnuts without permission, citing their mother's potential disapproval. His practicality extends to preferring functional lunchboxes filled with food over creatively arranged portions. Kitamoto also exhibits straightforwardness and humor, reassuring Natsume he needn't force socialization with Nishimura and teasingly supporting Natsume's rumored relationship with Taki. Despite a generally carefree demeanor, he engages in contemplation, reflecting on the fragility of family stability and drawing parallels between his circumstances and Natsume's orphaned background. Kitamoto's family includes his parents, younger sister Mana, a grandfather living separately, and an aunt and uncle residing near the sea. His father's illness profoundly shaped his worldview, strengthening his protective instincts toward his family. One significant afternoon after school, Kitamoto overheard Natsume seemingly struggling alone in a classroom; he mistook the disturbance for an unseen human threat. While seeking help, he discovered a bell that inadvertently resolved a supernatural conflict involving a yokai. Kitamoto witnessed anomalous events like vanishing teachers and unnatural wind phenomena, ultimately dismissing them as an extraordinary whirlwind. Walking home with Natsume afterward, he observed Natsume's detached calmness and reflected on his friend's deep attachment to their town. This incident heightened Kitamoto's awareness of Natsume's hidden burdens, prompting him to reflect on his own future uncertainties and the value of honesty with himself.