The Nakano Quintuplets are five identical sisters from the Nakano family. They live in the 30th floor of a luxurious apartment. The sisters live with just the five of them. Their mother passed away 5 years prior to the beginning of the main story, and their stepfather lives in a different residence. They were students of Kurobara High School before transferring to Fuutarou's school.
Each of the girls' name referencing a number, indicating the order of their birth.
The five sisters of Nakano Quintuplets have large dark-blue eyes, various shades of red hair-color, an average height, and a shapely figure. While they're physically the same, each girl have different hairstyles and accessories.
- Ichika has very short hair, her accessory is an earring in her right ear.
- Nino has very long hair and wears two butterfly-shaped ribbons on both sides of her hair.
- Miku has medium-length hair and wears a wireless headphone.
- Yotsuba has short hair and wears a ribbon atop her head.
- Itsuki has long hair and wears two star-shaped hairclips near both of her eyes.
The Nakano Quintuplets follow the "go-toubun" (five portions/part, divided equally) philosophy given by their mother. They consider themselves five parts of one whole, and have to share any kind of emotions together, such as anger, joy and love.
Each of the sisters have different traits and personality, some are similar, and some are contradictory. For example, both Nino and Itsuki are afraid of needles. Another similar traits would be Nino and Yotsuba, both have outgoing personality and therefore made a lot of friends. The Quintuplets' difference in personality can be taken from Miku and Yotsuba. Miku is a rather reserved, silent type girl while Yotsuba has an active and cheerful personality.
- Ichika is mature and playful.
- Nino is scheming and protective.
- Miku is silent and reserved.
- Yotsuba is cheerful and outgoing.
- Itsuki is serious and earnest.
The sisters have different unique skills, such as acting, cooking, and playing sports. All of them have bad grades, and they almost being held back a year. They have different subjects in which they excel, but even the grades of those subjects is still mediocre.
- Ichika's strongest subject is Maths.
- Nino's strongest subject is English.
- Miku's strongest subject is Social Studies.
- Yotsuba's strongest subject is Japanese.
- Itsuki's strongest subject is Science.
Ichika remarks that the girls are used to be close, hinting that their current dynamic is slightly distant than the past.This can be reinforced by the duo Nino-Itsuki and Miku-Ichika that are closer with each other, and seems doing activities together more often than with the other sisters. However, all five of them still share a strong bonds.
Most of the Nakano Quintuplets reject Fuutarou early in the story, due to various reasons, such as pessimistic towards their learning capabilities, being protective, expecting a better tutor, or having a quarrel with him. Over time, due to Fuutarou's hard work, they began to accept and appreciate him one by one. Some even began to develop romantic feelings to him.
How the Quintuplets address Fuutarou
- Ichika: Fuutarou-kun
- Miku: Fuutarou
- Yotsuba: Uesugi-san
- Itsuki: Uesugi-kun