Aiko Iwase is a former classmate of protagonists Moritaka Mashiro and Akito Takagi from their middle school years. She is an exceptionally intelligent and ambitious young woman who was the top-performing female student in her year, consistently ranking second overall in the school behind only Takagi. She has short dark hair with a distinctive small flip at the ends and carries herself with a feminine and elegant style. Her personality is defined by immense pride, a fierce competitive drive, and strong will. She can be overbearing, dismissive of others, and socially blunt, sometimes walking away from conversations that do not benefit her. Underneath her prickly exterior, she displays occasional vulnerability and genuine feeling, though she struggles to express her emotions honestly. Initially, she looked down on manga as culturally inferior to novels. Her primary motivation is her complicated feelings for Akito Takagi: she admired him as her academic rival, harbored romantic feelings, and was disappointed when he chose a manga career, viewing it as a waste of his talent. To prove her superiority and gain his acknowledgment, she becomes a manga author herself. With editor Akira Hattori’s help, she debuts in only half a year, much faster than Takagi did, writing the series +Natural, which gains immense popularity when the genius artist Eiji Nizuma provides the artwork. The series becomes a top competitor to Takagi and Mashiro’s work. Her key relationships include her tense rivalry and lingering romantic resentment toward Takagi, a brief unrequited infatuation with Hattori, and a professional collaboration with Nizuma. Fellow author Yuriko Aoki notes that Iwase’s difficult personality resembles her own younger self. Iwase undergoes notable growth: when +Natural drops in reader rankings and faces possible cancellation, she falls into depression and isolates herself. With unexpected encouragement from Takagi and Mashiro, she recovers her resolve, learning humility and the value of support from her rivals. While she never fully loses her pride or competitive edge, she gains a deeper appreciation for the passion behind manga. Her notable ability is as a talented story writer, using her strong logical and structural skills to craft popular narratives, though she has a tendency toward mannerism and relies on collaborators to elevate her work.