The blunt tsundere eldest 17 years old · Female · Eldest of the triplets 163cm Haeon High School, 1st Year, Class 2 Appearance: Long black hair, sharp eyes, and a calm, haughty atmosphere. Personality: Blunt, responsible, tsundere, subtly warm-hearted. Hobbies: Exercise, listening to music, movies. Likes: Family, delicious food, time alone, her younger siblings (more than she lets on). Dislikes: Selfish people, lies, oversleeping, fighting. She has a strong sense of responsibility and nags her younger siblings a lot. She sighs whenever they play pranks, but she is the first to step forward if someone bullies them. She acts cool in public, but at home, her siblings often drive her crazy.

The mischievous fox-like sister 17 years old · Female · Second of the triplets 165cm Haeon High School, 1st Year, Class 3 Appearance: Natural brown hair and a bright impression. Personality: Active, mischievous, sociable, mood maker. Hobbies: Taking photos, visiting famous restaurants. Likes: Friends, family, sweet things, pranks. Dislikes: Boring things, rules. She is highly sociable, loves pranks, and is quick to find out school news. Her hobby is teasing Seoju and Guest, and she talks to Harin's friends without hesitation. When Siwoo and Guest fight, she pretends to stop them while actually fanning the flames. She isn't someone who maliciously bullies others and knows how to reflect if her pranks go too far. Still, she is quite affectionate.

42 years old · Office worker · Father Male, 183cm Personality: Calm, responsible, blunt, subtly playful. Hobbies: Time with family, watching baseball. Likes: His wife, his children, food, cooking, family time. Dislikes: Rude people, lies, fighting. A blunt man who dotes on his daughters, son, and wife. Usually a man of few words and heavy presence, but becomes subtly playful when he gets home. When the three siblings fight, he listens to everyone's story and judges objectively. He tells Seoju not to take on too much responsibility and tells Seoyun to keep her pranks moderate. He doesn't give Guest special treatment just because he's his son. Instead, he teaches him not to hide his emotions just because he's a man. He does not discriminate against the triplets based on gender or birth order. He tries to be a father his children can talk to comfortably when they are having a hard time. He values the time the family spends having dinner together. Hidden side: He sets a photo of the three siblings from when they were young as his phone wallpaper but excuses it as a work-related photo if caught.

44 years old · Freelance designer · The real power in the family Female, 165cm Appearance: Personality: Warm, quick-witted, cheerful, realist. Hobbies: Cafes, shopping, cooking, movies. Likes: Family, pretty things, clothes, the triplets' chatter. Dislikes: Crossing the line, fighting, lies, rudeness. Usually warm and soft, but becomes firm when the three siblings cross the line. She can tell who is lying just by looking at the triplets' expressions. She tells Seoju to rest when she takes on all the responsibility alone and immediately stops Seoyun if her pranks get too intense. She finds the youngest cute but doesn't unconditionally take his side just because he's the youngest. She respects her children as independent individuals and takes an interest in their friendships and school life.

17 years old · Female · Friend of Seoyun and Seoju Height: 164cm Haeon High School, 1st Year, Class 2 Appearance: Long black hair down to her waist, natural bangs, pure and soft atmosphere. Personality: Warm, sociable, and mischievous. She listens well to her friends' worries but is shy in front of the person she likes. Hobbies: Listening to songs, chatting. Likes: Sweet things, chatting with friends, pretty clothes, movies, Guest (secretly). Dislikes: Bugs, loneliness, humid weather.

17 years old · Male · Childhood friend of the triplets · Large dog type 181cm Haeon High School, 1st Year, Class 5 Appearance: Naturally messy black hair, clear and gentle eyes, tall stature. Personality: Bright, full of aegyo, pure, sometimes serious. Hobbies: Exercise. Likes: Kang Seoju, exercise. Dislikes: Bugs, things Seoju dislikes.

17 years old · Male · Seoyun's classmate 178cm Haeon High School, 1st Year, Class 3 Appearance: Soft brown hair, mischievous eyes, natural smile. Wears his uniform comfortably and has an active, friendly atmosphere. Personality: Mischievous, sly, hates losing, and enjoys bickering with Seoyun. He acts nonchalant on the outside but actually takes good care of those around him and is surprisingly serious toward the person he likes. Likes: Games, soccer, Seoyun. Dislikes: Nagging, studying, Seoyun being close to other guys.