Itsuki Nakano

Itsuki is portrayed as an intelligent and confident student, but also a bit stubborn and headstrong at times. She is very close to her sisters and takes on a protective role towards them, especially when it comes to their father's, Maruo Nakano, expectations for their academic success. She is also passionate about food and aspires to become a food-related professional in the future.

Throughout the series, Itsuki's character undergoes significant development as she confronts her own feelings for Futaro and navigates her complicated relationships with her sisters. Her story arc highlights themes of family, personal growth, and the challenges of adolescence.

Itsuki is a serious looking girl with medium-length hair and an expressive ahoge. She has reddish-orange hair colour, ranging from light pink to salmon pink in Volume 1, and deep orange to orient red in Volume 4. Her notable accessories are a pair of star-shaped hairpins near both of her eyes, which Futaro Uesugi called unfashionable at one point. Like her sisters, she has dark blue eyes, an average height, and a well-endowed figure. In class, or when she does activities that involve academics, she wears glasses.

Itsuki is noted to be "cute" by her classmates and she looks very similar to Rena Nakano, according to Shimoda.

She wears her uniform normally without any accessories, like most of the girl students, and on occasion, she wears a handbag.

Itsuki is a serious and earnest girl who usually wakes up early compared to her sisters. She is well-mannered; never being late or missed a class,1 and always speaks formally. In the Japanese script, she almost exclusively speaks with a keigo speech pattern. Nino, her older sister, comments that Itsuki is too straight-laced.

Itsuki is a girl who bears grudges, as shown when she rejects Futaro's tutoring partly because of a previous quarrel they had. She is also someone who can't be honest with herself and has difficulties being more straightforward. Both of these qualities often make her struggle on her own. She is easily agitated, be it about unfavourable situations, scary things or her stubborn self.

She has a huge appetite and is frequently seen eating something or being hungry throughout the series. It appears that she doesn't mind treating her sisters unfairly when it comes to food-related topics. This shows where during one scenario when she proposed to her sisters to share their cakes; suspected to sample all the flavours by Ichika.

According to Futaro, each Nakano has their own characteristics regarding their sheets. In Itsuki's case, she would rather use an eraser than scribble on them.

Itsuki is commended as a diligent girl, and she does things very precisely. She is also perceptive and has a good sense of detail. Despite that, she has an awful sense of direction. Her poor sense of direction is first mentioned, when she became sensitive to the cold so she sneaks into Nino's futon. She also has poor eyesight and is often seen wearing glasses. She has good observation and deduction skills. On exams, Itsuki generally scores high compared to her sisters, with her strongest subject being Science.

In spite of her excellent deduction skills, she was the last of her sisters to realise Miku's affection towards Futaro.