Sempai (先輩 Senpai) is the title character of the Magical Sempai manga and anime. She is a third year high school student with an interest in performing magic tricks. She starts her own Magic Club and recruits an assistant known only as Assistant. Unfortunately, Sempai has severe stage fright and constantly messes up her tricks, much to the dismay of Assistant. Sempai also has a habit of partially exposing herself and getting into embarrassing situations, as well as making double entendres or suggestive comments.
Because of her stage fright, Sempai is unable to perform tricks correctly when others are watching. However, she is able to perform tricks flawlessly when she is alone. Sempai is good at painting, and she is very athletic and can easily catch her Assistant when he tries to run away from her.