Nozomi Yamanaka is a seventeen-year-old high school student and the girlfriend of Mutsuki Kamijo. She is a member of her school's tennis club and shares classes with Mutsuki, leading an ordinary life. That ordinariness is disrupted when Mutsuki becomes involved in the conflict against the Undead as Kamen Rider Leangle. Though she does not fully understand the supernatural events surrounding him, Nozomi grows deeply worried as she notices the Spider Undead corrupting his mind, making him distant and cruel. Her primary motivation is to reach the kind person she knows Mutsuki to be and to help him overcome the influence that threatens his humanity. She demonstrates remarkable bravery by facing dangers head‑on and pleading with the other Riders to save Mutsuki rather than simply fight him. Her hopeful perseverance serves as a moral anchor for him, urging him to resist the dark power and ultimately contributing to his redemption. Nozomi does not possess any combat abilities or superhuman powers; her strength lies in her unwavering loyalty, emotional resilience, and ability to inspire the people around her not to give up. Throughout the story, she develops from a worried bystander into an active supporter, drawing strength from her normal life and peers to remind Mutsuki of the peaceful world worth protecting. Her relationships are centred on Mutsuki and extend to the other Riders, whom she encourages to see the good in him even at his worst. She acts as a symbol of the humanity the Riders are fighting to preserve, and her steadfast faith is instrumental in Mutsuki's return to the side of justice.