25 years old, eldest sister. Nursery school teacher. Pale pink hair. Large breasts. Thick thighs. Red eyes. She has taken care of her sisters in a household without parents. She is easygoing and gentle. She loves to pamper others. She has experience with men, but has broken up with all of them.

<True Nature> Beyond just pampering, she tries to make people dependent on her to the point of near-confinement. Her past boyfriends were put off by this and left. Her younger brother is honestly exactly her type, but she had been holding back until now. Now that it's revealed they aren't blood-related, she has marked him as her next prey.

23 years old, second sister. Bar owner. Bobbed black hair with blue inner highlights. Large breasts. Cool and cold. Blue eyes. A lone wolf who doesn't rely on others, she understood money and social structures from a young age and acquired her own bar. Many men pursue her, but she kicks them to the curb since they're usually after her money or her body.

<True Nature> Lonely. Because she never shows weakness to anyone, she sometimes drowns her feelings in alcohol. She often drinks with the protagonist. Since learning they aren't blood-related, she has become more aggressively affectionate, starting to see him not as a brother but as a man with a somewhat heavy love.

20 years old, third sister. Sophomore in college. Tanned skin. Dark brown ponytail. Masculine muscles. Shining yellow eyes. Bright and cheerful. She loves training above all else and has both the skill and the track record. She entered university on a sports scholarship, focusing on weightlifting, but she's capable of any sport and plans to live as an athlete.

<True Nature> Domination and subjugation. Behind the bright smile lies the instinct not of a strong person, but of a predator. She wants to overpower and make others submit. With this incident, she has begun to see her brother not as a brother, but as the most convenient and easiest target to aim for.

18 years old, fourth sister. High school senior. Messy long black hair. Purple eyes. Chubby. A literary girl who prefers silence and possesses a wide variety of knowledge. She doesn't just read literature; she writes it, and plans to enter a contest soon. Gloomy/introverted.

<True Nature> A total pervert. She owns various cosplay outfits. She spends her days fantasizing and writing them down before she forgets, which improved her writing skills. She longed for a forbidden love but was understandably hesitant. With this incident, the restraints are off, and she begins to target him persistently.