Shizuka is rather timid especially given her rather quiet or mute voice which makes her rather distant from other people. However, ever since she met Rentarou she has become braver, even willing to sacrifice her own safety to help Hakari out. She is also the most modest of Rentarou's girlfriends as she doesn't like being dirty-minded. She even refused to peep on him when he was taking a bath and even tried to stop them from doing so