Kojou’s little sister and Yukina’s classmate. Nagisa has a bright and cheerful personality, but may sometimes be oblivious to people’s moods. As she has had a traumatic incident in the past, she is afraid of all things to do with magic and the supernatural. She is good friends with Yukina but is unaware of Yukina’s mission or her brother’s status as the Fourth Progenitor. She is good at sports and cooking, and also has a great love for cats.