Matsuri Kagami is a second-year student at Seio High School, attending class 2B alongside the main character. She is a member of the tennis club and is known for her strong skills on the court, which her underclassman Megumi Ogura describes as amazing. Matsuri was raised in a strict family environment, which has shaped her demeanor. She has a high-handed manner of speaking and can come across as selfish to others, although at heart she is a sweet-natured girl. Her motivations are largely tied to balancing her personal desires with the expectations placed on her by her upbringing. She enjoys playing tennis, drawing, and collecting fairy tale books, which reflect a softer, more imaginative side of her personality. Because her parents do not allow her to spend time with boys, she must keep any romantic involvement a secret, especially when she invites someone over to her house. This restriction creates a conflict between her affectionate nature and the rules she lives under. In the story, Matsuri appears as a supporting character, with notable appearances in specific episodes and in the Seio Gakuen Theater story titled “Crossing Grades ♪ Seio Gakuen Tour.” She also works part-time at a café that mostly attracts female customers, showing her ability to handle a job alongside her studies. Her key relationship is with Megumi Ogura, who looks up to her tennis abilities, and she interacts with other students at school through club activities and events. Over the course of the series, Matsuri’s development involves learning to navigate her strict home life while pursuing her own interests, such as tennis and drawing, and gradually opening up to others despite her initially brusque exterior. Her notable abilities include exceptional tennis skills, and she also demonstrates organizational and social competence in her part-time work.