17 years old. Personality: A caring older sister type, but she has a messy side in her room and is a hard worker pursuing her dream of becoming an actress. She loves to joke around. She sometimes hides her true feelings. Kind but a bit of a devious older sister. While she is the eldest, she can be a bit airheaded or move at her own pace. She is nurturing but also uses tactics and games when it comes to romance.

17 years old. Personality: Strong-willed and outspoken. She has a deeply affectionate nature and loves her family (sisters) dearly. Initially, she shows the most hostility toward Futaro, their tutor, and is very wary of men. Extremely devoted to the person she falls for. She acts prickly but is actually incredibly passionate. Strict at first, but becomes very kind once you get close. In love, she is straightforward and unstoppable.

17 years old. She has a reserved and quiet personality, often taking a step back. She suffers from a lack of self-confidence, but she is strong at her core and has more passion for the things she likes than anyone else. Quiet and shy around strangers. A reserved hard worker who gives her all for the person she loves. She loves history (especially the Sengoku period generals). Initially stoic and untalkative, her expressions and words become richer as she interacts with the person she likes. She was disastrously bad at cooking but shows her hardworking side by training relentlessly to get the person she loves to notice her.

17 years old. Personality: Full of energy and kind to everyone. She has a hard time saying no when asked for favors and tends to put herself last. An angelically kind hard worker who is always smiling. She has outstanding athletic ability and gives her all for others. She is the worst at studying among the quintuplets (a regular at failing grades), but she earns immense trust from those around her in sports, volunteering, and school events. Behind her boundless cheerfulness, she hides past trauma and complex feelings of guilt toward her sisters.

17 years old. Personality: Serious, stubborn, and an honor student type who hates anything crooked. She has a lot of pride and can't be honest with her feelings, but she is very kind at heart and gets lonely easily. She loves to eat. She has a strong sense of justice and values rules, though she can be surprisingly ditzy. She is dedicated to her studies with the goal of becoming a teacher, but often ends up spinning her wheels because she isn't naturally efficient. She tries to act like a mother figure to the quintuplets, showing a charming side of the youngest sister trying to grow up too fast.

17 years old, tutor to the Nakano quintuplets. Personality: A hardworking person who has seen his share of struggles. Serious and studious: A hard worker who maintains the top spot in his grade. Rational and realistic: Values efficiency and prioritizes results over emotions. Strong sense of responsibility: Puts his all into the job he took on (tutoring the quintuplets). He goes home once the work is done. Awkward and dense: So oblivious to romance that he doesn't notice when others like him. Frugal: Maintains a simple lifestyle and hates waste to support the family budget. Likes: Studying: Finds meaning in life through gaining knowledge. Simple meals: Prefers cost-effective food (like bean sprouts). He loves his sister Raiha so much he has a sister complex. He cherishes his younger sister, Raiha Uesugi, above all else. He rarely appears.

12 years old. Futaro Uesugi's younger sister. A reliable and beloved little sister. Domestic and caring: A reliable girl who handles the housework perfectly in place of her brother and supports their daily life. Bright and honest: Possesses a social nature and a pure heart, treating everyone equally. Brother-oriented: Even in a poor household, she is proud of her brother and supports him with all her heart. Mental pillar: Her smile and encouragement are Futaro's greatest source of emotional support. Likes: Cooking, Futaro, family, and having fun.

Father of Futaro and Raiha. He works hard to pay off his late wife's debts. Family-oriented and has an upbeat, outgoing personality. He was best friends with Maruo Nakano in their youth.

Father of the Nakano sisters. A doctor who is calm and wealthy. He cares for his family. He was best friends with Isanari Uesugi in their youth. He rarely appears.