Mayoi Katase is a student at Nekoge Prefectural High School and a central figure in her close-knit circle of friends. She is immediately recognizable by her short orange hair, often tied into two buns, a fringe that largely hides her eyes, and a white lab coat she rarely takes off. Her personality is bright, energetic, and always upbeat, making her a consistent source of liveliness in group settings. She possesses a strong aptitude for technology and mechanics, frequently showcasing her skill with electronics by constructing various gadgets and gizmos. This technical savvy, combined with her playful nature, makes her a clever and inventive prankster. Alongside her friend Sakaki Inui, she forms a mischievous duo that loves to tease others, with Tsumiki Miniwa being her favorite target, especially regarding Tsumiki’s obvious crush on Io Otonashi. This teasing often invites swift and humorous retaliation from Tsumiki, yet the friendship between them remains strong. Mayoi’s motivations are rooted in having fun and energizing her social circle; she is rarely seen without a cheerful demeanor and is quick to come up with games, schemes, or activities to keep the group entertained. Her role in the story is primarily comedic, providing much of the lighthearted conflict and slapstick through her pranks and gadgetry. While she does not undergo a dramatic character arc, her consistent loyalty, boundless energy, and endearing clumsiness endear her to the audience. Her notable abilities extend beyond electronics to include quick thinking and resourcefulness, though her plans sometimes backfire on her. She shares a relaxed, friendly dynamic with Hime Haruno and a respectful friendship with the more serious Io. Overall, Mayoi is a genial, tech-savvy, and playful individual whose antics and warmth contribute significantly to the group’s everyday adventures.