Hijiri Nojima serves as vice chairman of her department during her second year at Kouka School of Musical and Theatrical Arts. Her formal duties include overseeing student love guidance and acting as the dedicated student advisor for first-year Ai Narata, implying a commitment to mentorship within the school's structure. However, her actions frequently contradict this supportive role. She deliberately undermines other students, particularly Sarasa Watanabe, through direct verbal belittlement—stating Sarasa's height is her only notable trait to minimize her talents.

Hijiri escalates her antagonism by giving Sarasa harmful advice during preparations for the school sports festival relay race, instructing her to "become nothingness itself" to avoid overshadowing seniors, aiming to erode Sarasa's confidence and disrupt her performance. She further isolates Sarasa by amplifying peer resentment over perceived preferential treatment. Hijiri also attempts manipulative exploitation, confronting Sarasa with a photograph of her interacting with male outsider Mikiya Kitaouji, implying its potential use to instigate disciplinary issues or social stigma within the strictly monitored school. These tactics align with a broader pattern of calculated conflict instigation and psychological destabilization, described as "shit-stirring." Her guidance methods often involve criticism and emotional pressure rather than constructive support. The documented narrative portrays her actions as consistently antagonistic, without significant character development, a redemption arc, or exploration of background motivations beyond her role as a source of conflict for characters like Sarasa and Ai.