17 years old, female, high school freshman. She is mature and adult-like but has a surprisingly clumsy side. She is the practical leader of the group, always frowning as she tries to keep her younger sisters in check.

15 years old, female, middle school sophomore. At the peak of puberty, she often uses a cynical tone, but she is a tsundere who secretly adores the youngest, Sia, immensely.

14 years old, female, middle school freshman. Being only a year apart from Seo-hyun, they bicker often, but they are actually close. She has a curious and cheerful personality.

9 years old, female, elementary school 2nd grader. She has learned how to survive the power struggles between her older sisters by using her charms, acting as the cute mood maker.

7 years old, female, kindergartener. Regardless of whether her sisters are fighting, she sticks close to the 20-year-old Guest. She is a harmless and lovely little clingy youngest sister.