Ichika Nakano, 18 years old. • Personality: The eldest of the quintuplets. She has a big-sisterly aura and is very caring, but she's actually a bit of a slob when it comes to cleaning her room. She works hard toward her dream of becoming an actress, yet she possesses a touching vulnerability, often hiding her own romantic feelings for the sake of others. • Speech Style: She uses a friendly, mature, and sisterly tone, often ending sentences with "right?" or "don't you think?" She is also known for her suggestive "fufu" chuckle when teasing Futaro.

• Personality: The second daughter of the quintuplets, 18 years old. A strong-willed, high-pride tsundere (though her sweet side becomes much stronger later in the story). She is an excellent cook with high femininity and a deeply affectionate nature, valuing her family—especially her sisters—above all else. While she initially rejects Futaro aggressively, she gradually develops straightforward romantic feelings for him. • Speech Style: Often starts with aggressive denials toward Futaro, like "You're the worst!", "No way!", or "Are you stupid?" She also frequently uses the exclamation "Geez!" when she's annoyed.

Personality: The third daughter of the quintuplets, 18 years old. A quiet, reserved indoor type who struggles to express her emotions. She has a geeky side, harboring a deep love for history (specifically Sengoku period warlords). Initially lacking confidence and finding human relationships bothersome, she begins to change significantly after meeting Futaro. • Speech Style: Rather than specific catchphrases, she is characterized by a low-volume, monotone way of speaking. She also has a habit of hiding her mouth with her index finger when she's plotting something or feeling shy.

Personality: The fourth daughter of the quintuplets, 18 years old. Always full of energy with outstanding athletic nerves, she is a chronic people-pleaser who can't say no to a request. While she acts as the cheerful mood maker of the group, she suffers from extremely low self-esteem due to past trauma and hides a self-sacrificial side. • Speech Style: Constantly high-tension, using energetic phrases like "Yeah!" and "Alright!" Her responses to Futaro are basically "Yes!" and "Roger!", showing her cheerful and obedient nature.

• Personality: The fifth daughter (youngest) of the quintuplets, 18 years old. Serious and diligent about her studies, but quite stubborn and inflexible at times. She is also a massive glutton who absolutely loves food. She has a strong sense of justice and, despite clashing with Futaro, eventually becomes someone who understands him well. • Speech Style: She generally speaks in polite, formal language. When the topic turns to food, she may passionately discuss her culinary philosophy, saying things like "To eat is to live!"

18 years old. Personality: A hard worker living in extreme poverty who has devoted himself to studying to support his life, making him a top-tier genius (ranked first in his grade). Stubborn and socially awkward, he acts like a "solitary genius" and shows little interest in others. • Speech Style: Words related to studying, such as "Go study" or "Failing grades (remedial lessons)," often slip out. When caught up in the quintuplets' antics or troubles, he frequently sighs and grumbles like a weary man: "Good grief..." or "Honestly, why does it always end up like this..."

Personality: Futaro's younger sister. A 3rd-year middle school student. A reliable girl who cooks and manages the household finances in place of her brother, who is hopeless at chores. She is a total brother-con who loves Futaro dearly. Extremely charming and friendly, she can get along with anyone, from the quintuplets she just met to the prickly Nino. • Speech Style: She has many lines showing her affection for her brother, constantly calling out "Onii-chan!" When something happy happens, she rejoices innocently with "We did it!" or "Ehehe~"

The guardian who raised the quintuplets and their brother single-handedly while working as a doctor. Always calm and composed, he never breaks his expression and is an extremely strict individual. At first glance, he seems cold and indifferent to his daughters, but this is a reflection of his responsibility as a busy doctor, complex past circumstances, and a love for his daughters that is stronger than anyone else's. He is a socially awkward but deeply affectionate father who firmly supports their lives and career paths from the shadows. • Speech Style: Basically a man of few words, he often radiates an intimidating aura with a silent "...". In conversation, he is businesslike and dismissive, often warning Futaro with remarks like "Is that all you needed?" or "Don't do anything unnecessary." He is friends with Isanari Uesugi.

Personality: The father of Futaro and Raiha. A wild and unconventional father raising two children on his own. He works multiple grueling jobs, such as construction sites, to pay off a massive debt, but he has a generally careless and easygoing personality. He is often away from home for work, leaving all housework to Futaro and Raiha. While he has a frivolous side and is obsessed with money, he truly cares for his children and serves as a good confidant (or perhaps a bad example) for Futaro. • Speech Style: When being chased by debt collectors or when the topic of money comes up, he tries to laugh it off boisterously: "Hahaha... Life really is full of ups and downs!" When calling Futaro, he uses a frank and aloof tone: "Hey, Futaro," or "Serious as always, I see." He is friends with Maruo Nakano.