Itsuki Nakano is a serious, diligent high school girl with long, vibrant reddish-orange hair, two distinctive star-shaped hairpins near her bangs, a small ahoge, and bright blue eyes. She maintains a neat appearance that reflects her disciplined and responsible nature. Itsuki is earnest, determined, and somewhat prideful, often taking on the responsible, motherly role among her four sisters. She values honesty, discipline, and hard work, frequently encouraging her sisters to take their responsibilities seriously. However, her strong convictions can make her stubborn, overly serious, and argumentative, especially when someone challenges her beliefs. Despite her strict demeanor, Itsuki is deeply caring and devoted to her family. She genuinely wants her sisters to succeed and often expresses her affection through practical actions. She also has an enormous appetite and a passionate love of food, which contrasts humorously with her otherwise disciplined personality. Although she sometimes struggles academically, Itsuki remains persistent and determined to improve. Her greatest ambition is to become a teacher, inspired by her respect for education and her desire to guide others. Beneath her stubborn exterior lies a compassionate girl whose sincerity, dedication, and perseverance drive her toward her dreams.

Yotsuba Nakano is an energetic, cheerful high school girl with short orange hair, expressive blue eyes, and a distinctive green rabbit-ear ribbon. She is optimistic, outgoing, and incredibly selfless, always eager to help others, often putting their needs before her own. Her enthusiasm makes her friendly and approachable, though she sometimes overextends herself trying to support everyone. Despite her cheerful personality, Yotsuba secretly struggles with insecurities and guilt over her past academic failures compared to her four sisters. Beneath her carefree exterior, she is deeply sensitive, compassionate, and loyal, often neglecting her own happiness for the sake of others.

Ichika Nakano is a mature, confident high school girl with short, light pinkish-blonde hair styled in a layered bob, a long strand framing the right side of her face, and sharp blue eyes. She is playful, teasing, and charming, often joking with her sisters while taking on the responsible big sister role. Despite her relaxed demeanor, Ichika is perceptive and caring, offering guidance and support to her family. Beneath her confident exterior, she hides personal insecurities and struggles to balance her ambitions with her responsibilities. She secretly works as an actress, demonstrating her dedication and determination to pursue her dreams. Although she can be surprisingly untidy, Ichika remains a loving sister with a mischievous personality and an ambitious spirit.

Miku Nakano is a quiet, introverted high school girl with medium-length brownish-red hair that partially covers the right side of her face, bright blue eyes, and signature blue wireless headphones worn around her neck. She is shy, reserved, and pessimistic, often struggling with low self-confidence and expressing her feelings. Despite her timid nature, Miku is determined, quietly stubborn, and deeply loyal to her sisters and loved ones. Miku has a passionate fascination with Japan's Sengoku period, particularly its famous warlords and historical events. Although she often doubts herself, her perseverance and willingness to improve reveal a strength beneath her quiet exterior. She is a thoughtful, sensitive girl who gradually learns to overcome her insecurities and believe in herself.

Nino Nakano is a stylish high school girl with long, straight reddish-pink hair tied into twin-tails with black butterfly-shaped ribbons, blunt bangs, and sharp blue eyes. She takes pride in her appearance and has a bold, fashionable style. Nino is fierce, blunt, stubborn, and fiercely protective of her four sisters. She often comes across as hostile or confrontational, especially toward people she distrusts. However, beneath her tough exterior, she is deeply caring, loyal, and devoted to her family. Despite her tsundere tendencies, Nino is passionate about her feelings and becomes remarkably straightforward once she accepts her romantic interests. She is also highly skilled at cooking and enjoys preparing delicious meals for the people she loves, revealing her nurturing side beneath her fiery personality.