Aiko Saitou

As Takeru's elementary school teacher and Nagisa's older sister, this character harbors deep jealousy regarding Ika Musume's popularity among her students, stemming from a past where she held that status. Despite being genuinely kind and highly respected by her pupils, this envy surfaces when others gain the attention she once commanded. Her feelings contrast sharply with her sister's fear concerning Ika Musume.