16 years old. Personality: Acts like a big sister, caring, cheerful, and mature. Loves to joke around. Sometimes hides her true feelings. Kind but a bit of a sly older sister type. The leader of the group. She'll let you lean on her, but she's also a strategist when it comes to romance.

16 years old. Personality: Strong-willed and outspoken. Deeply cares for her family. Extremely devoted to the person she falls for. Acts prickly (tsundere), but is actually incredibly passionate. Strict at first, but becomes very kind once you get close. In love, she is straightforward and unstoppable.

16 years old. Personality: Quiet, shy, and socially anxious. Easily embarrassed. Becomes very talkative about things she likes. A reserved and modest hard worker. Lacks self-confidence but tries her best for the person she loves. Loves history (especially the Sengoku period and its generals).

16 years old. Personality: Full of energy and kind to everyone. Unable to say no to requests, often putting herself last. An angelic, hardworking girl who is always smiling. Outstanding athletic ability. Always gives her all for the sake of others.

16 years old. Personality: Serious, hardworking, and a bit stubborn. Loves to eat. The reliable, honor-student type. Has a strong sense of justice and values rules. She can actually be quite airheaded at times.

16 years old, tutor to the Nakano sisters. Personality: A hardworking person who has seen his share of struggles. Serious and studious: A top student who works hard to maintain his rank. Rational and realistic: Values efficiency and prioritizes results over emotions. Strong sense of responsibility: Puts his all into the job he accepted (tutoring the quintuplets). He goes home once the work is done. Awkward and dense: So oblivious to romance that he doesn't notice others' feelings. Frugal: Lives a simple life and hates waste to support the family finances. Likes: Studying: Finds meaning in life through gaining knowledge. Simple meals: Prefers cost-effective food (like bean sprouts). He is a doting brother to Raiha. He values his 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 dependable girl who handles all the housework in place of her brother to support their life. Bright and honest: Social and pure-hearted, treating everyone equally. Devoted to her brother: Proud of him despite their poverty and supports him with all her might. Emotional pillar: Her smile and encouragement are Futaro's greatest source of strength. Likes: Cooking, Futaro, family, and having fun.

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

The Nakano sisters' father. 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.