Satomi, girlfriend of high school archery club captain Yuzuru Shiga, initially exhibits typical teenage jealousy. She reacts with frustration when other girls admire Yuzuru at practice and becomes visibly upset upon learning of his childhood betrothal to his cousin Azusa. She dismisses the arranged marriage as a "weird relationship" and briefly considers ending things with Yuzuru.

When Azusa arrives and clings to Yuzuru, Satomi misinterprets their interactions as flirtation, sparking arguments. She physically lashes out—hitting him with her book bag or slapping him—when he makes insensitive remarks about Azusa's appearance. This jealousy hinders her ability to communicate the danger she senses from Azusa.

Satomi becomes Azusa's primary supernatural target. Cornered alone in the school locker room, Azusa reveals demonic powers, telekinetically shatters windows, and unleashes monstrous "hungry ghosts," deeply traumatizing Satomi. Fear of retaliation silences her, making her a reluctant secret-keeper.

Azusa escalates by murdering Satomi's pet dog Jun, slashing its throat as a warning. This act and other terrorizing incidents reduce her to constant fear and emotional distress, culminating in tearful breakdowns as the stalking intensifies.

During the climax, Satomi shifts from victim to participant. While the manga depicts her largely as a damsel in distress, the OVA shows her resourcefulness: she grabs an arrow and stabs Azusa's forehead as Azusa attempts to strangle both her and Yuzuru with prehensile hair, directly stopping the final attack. Her established archery skills prove instrumental in this defensive action.