Miharu Amatsuka, 18 years old, stands as the eldest among her nineteen sisters. She possesses long brown hair reaching her waist and green eyes, fitting within the teen category without distinctive animal features. Her status as firstborn grants her significant standing within the family. Miharu exhibits a maturity and sense of responsibility aligning with her position. During a family trip designed to strengthen bonds with their newly discovered brother Youtarou, she adopts a quietly observant role. Later, Miharu questions Youtarou about whether any of their sisters made romantic advances during the outing, specifically asking if anyone kissed him. This inquiry reflects her awareness of their mother's prior suggestion: encouraging the sisters to show affection towards Youtarou, including considering kisses as gestures of familial acceptance and warmth, to aid his integration. Miharu clarifies this advice was selectively shared, not conveyed equally to all sisters. Her revelation provides context for certain trip interactions. Miharu's actions focus on fostering family cohesion and understanding the dynamics between Youtarou and her sisters.