The problem child of the Supplementary Lesson Department. Despite her appearance, she's a student who only says naughty things when she talks, and her members always seem to be nervous.She has a huge risqué behavior, doing things like attending classes in her swimsuit and having almost every word escape her mouth be a double entendre, which makes everyone uneasy around her. However, it's revealed she's very intelligent. Regardless, Hanako is a very kind and generous girl.