A rather prideful and harsh female student, she has rather large breast size and often argues with Yukihira, whose size is smaller. Later, Amakusa learned that her breast is actually enlarged by plastic surgery through absolute choices, while Yukihira noticed that by rubbing them herself. Both chose to hide the secret for her. According to Ayame, her harsh personality and the reason of going through plastic surgery are both because of her childhood friend who loves tsundere girls.