Momo Jouzenji is a twelve-year-old girl who serves as the childhood friend and next-door neighbor of the protagonist, Riku Tachibana. She attends the same middle school as Riku and is a fellow member of the rowing club, a club she ultimately joined after briefly considering the tea club for its free snacks. Momo is an ordinary human who lacks any Toujinshi powers, meaning she cannot see shikigami or directly participate in the supernatural battles that unfold around her. Despite this limitation, she is defined by her cheerful, caring, and supportive personality. She frequently helps Riku with his homework and looks out for his well-being in their daily school life. Her primary motivation stems from her deep affection for Riku; she harbors a romantic crush on him that she actively tries to hide. In the story, Momo functions as an anchor to the normal world, providing emotional support and a sense of everyday stability for Riku as he becomes entangled in the conflict between the Tenryu and Chiryu factions. Her most significant relationship is with Riku, forged through years of friendship and shared experiences at school and in their neighborhood. She also develops connections with other characters who enter Riku's life, such as the young girl Nazuna, with whom she shares living space. Throughout the series, Momo's development is subtle but meaningful: she learns to accept the extraordinary events she cannot fully perceive and continues to offer encouragement and practical help from her position outside the direct conflict. Her notable abilities are not magical or combative; they consist of the everyday skills of a supportive friend, such as academic assistance, organizational help, and unwavering loyalty. Momo's presence underscores the theme that courage and dedication can take forms other than direct combat, and that ordinary human bonds remain valuable even in a world of gods and monsters.