Kaoru Seta plays guitar in Hello, Happy World and studies theater at Yotsuba Women's University. She cultivates a princely persona, calling admirers her "fleeting kittens," boosting her popularity at Haneoka Girls' High School. This persona stems from childhood shyness and loneliness after her friend Chisato moved away, leading her to adopt this outgoing façade to attract friends. Despite her confident exterior, she harbors vulnerabilities like a fear of heights and discomfort with horror themes. She often complies with requests even when uneasy, such as skydiving or balancing on a ball while playing guitar at Kokoro’s insistence. This willingness highlights her underlying desire for acceptance. Kaoru demonstrates genuine kindness and dedication to her band and fans. She meticulously remembers details about admirers and works diligently during events like White Day to reciprocate their support. Her commitment to spreading joy aligns with Hello, Happy World’s ethos, though she occasionally questions her role. Her theatrical flair extends to costumes like a phantom thief outfit, which she maintains earnestly even when others perceive it as part of her character. Her character development includes gradual self-acceptance. While she relies on her princely persona as an "ideal self," she exhibits moments of authenticity, particularly around childhood friend Chisato, where her shyness resurfaces. Events like the Romeo-themed play challenge her fears of heights and ghosts, forcing her to confront vulnerabilities within her constructed identity. Despite not fully abandoning her façade, she integrates it into her band identity, using it to contribute to Hello, Happy World’s mission of creating smiles. In the *Garupa☆Pico ~Ohmori~* mini-series, her traits are humorously amplified. She engages in exaggerated activities like skydiving despite visible fear, reinforcing her role as a dedicated but internally conflicted performer. These segments emphasize the comedic contrast between her composed persona and situational anxieties without altering her core characterization.