Shiina Mizuka

Mizuka, a very lax character shown quickly to have various traits such as having the largest breast size and also being the oldest of the crew. Despite the age difference between Naoto to be only a few months, Mizuka refers herself as "Naoto’s older sister", and acts this way as well. Contrary to her personality of being laidback, Mizuka is extremely intelligent–receiving top grades in her classes. However, her weakness is that her ridiculously low physical endurance limits her to walking to school. Her intelligence, however, corresponds to her sharpness in detecting changes to the people around her.