Kaguya Shinomiya

One of the main characters of the series. A female student in Class 2-A → Class 3-A of the high school division. She is the vice president of the student council and a member of the archery club, with skills at the national competition level. She holds a first-degree black belt in Aikido and a second-degree black belt in Judo. Born on January 1st, blood type AB.

She is the daughter of the powerful Shinomiya Group, which boasts total assets of 200 trillion yen, and is described by Erika as the "Princess of the Second Year" due to her stunning beauty. She is an illegitimate child with three half-brothers. She refers to herself as "watashi."

She has long black hair tied at the back, with a variety of ribbon colors. Although she is left-handed, she has been trained to use her right hand, but her left hand is stronger. She has hypersensitive hearing and dislikes loud noises. She has a modest chest size and feels complex emotions about Chika's larger chest.

Due to her prestigious lineage, she excels in academics, arts, music, martial arts, and anything she tries, making her a "versatile genius." She is quite jealous and has once unilaterally ended her friendship with Chika in her mind after seeing her get close to Miyuki.

Due to the Shinomiya family's upbringing, she struggles to understand others' feelings, often looking down on others or considering their utility first, but she dislikes this aspect of herself. Initially, she had a prickly demeanor that kept people away, but joining the student council helped her learn to be more sociable. While fundamentally self-centered, she also has a kind side, such as helping children in need. She is steadfast in her rules and declarations.

The Shinomiya family's main residence is in Kyoto, but she lives in a villa in Sengakuji. Her daily needs are taken care of by a housekeeper, she uses a private car for school, meals are prepared by a professional chef scouted from a three-star hotel, and she carries 100,000 yen in cash and a black card in her wallet, leading a very sheltered life. As a result, she is naive and unfamiliar with the common world, and she admires ordinary things. She is generally an analog person with poor IT skills, having used the same flip phone since kindergarten, but she switched to a smartphone after it broke in the series.

She has feelings for Miyuki but cannot be honest due to her pride and has a complex about his kindness, fearing he might not accept her bad personality. She devises strategies to make Miyuki confess to her but stubbornly refuses to acknowledge her feelings as love. She has created a manual for various scenarios of Miyuki's responses. She rarely gives her all in competitions, believing "defeat is also a survival tactic," but she puts her all into academics, though she cannot surpass Miyuki and is obsessed with defeating him. Her feelings for Miyuki once led her to collapse and be taken away by ambulance, prompting her to develop a routine of placing her right hand on her left cheek to regain composure.

She doesn't fully understand what love is but is seen as a love expert by those around her and is often consulted by female students. She was raised with extremely limited information about sex, thinking "first experience" meant a kiss and having very low tolerance for dirty jokes, but she is gradually gaining sexual knowledge through self-study and the influence of those around her.

She has an unstable emotional side, showing different personalities to the point of being almost like multiple personalities. In her mind, these sides debate in what she calls "brain (internal) battles," with scenes depicting their interactions.

As an illegitimate child whose mother died shortly after giving birth to her, her position in the Shinomiya family is weak. In her childhood, she shared this secret with a close friend under the promise of secrecy, but it was leaked, leading her to test potential friends by sharing a "secret" and seeing if it remains undisclosed over time.

Kaguya frequently appears muttering "How cute..." in a condescending manner, but most of these instances are Miyuki's imagination. Kaguya herself imagines Miyuki saying "How cute you are" if she shows weakness.

In the live-action adaptation, she is portrayed by Kanna Hashimoto, and in the series, Miyuki describes her as "as beautiful as Kanna Hashimoto!! [Mama]."

Kaguya (Ice)

A state where Kaguya's logical side is emphasized. It symbolizes submission to restraint, emotional suppression, disappointment in life, fear of others, and aggression.

This ice side used to be more prominent, but it has surfaced less frequently since meeting Chika and Miyuki, now only appearing during times of anxiety, stress, worries, or menstrual irregularities. She looks significantly different from her usual self, with long hair and a lack of facial expression changes. The nickname "Ice Princess Kaguya" from her middle school days comes from this state, characterized by a ruthless and unapproachable personality, making others, except Chika, avoid her. According to Kashiwagi, she is "100 times smarter than usual."

This ruthlessness stems from her inability to understand others due to differences, leading to a strong inferiority complex and self-loathing, with her suppressed emotions manifesting straightforwardly.

Kaguya (Fool)

A state where a part of her inner self, suppressed under a repressive environment, is emphasized. It surfaces strongly when she feels safe, happy, or has a cold. She has low intelligence and flowers growing from her head. This aspect, which should have been acquired during healthy human development, was abandoned due to her upbringing. It was rediscovered through interactions with the student council members and is called a newcomer by Ice Kaguya, who sees it as a hindrance to her genius thinking.

Kaguya-chan

According to Chika, this "rare Kaguya" appears only when all conditions of 60% happiness, 40% escapism, and sleep deprivation are met. Chika has only seen it three times. The personality is Kaguya (Fool). In the series, she is depicted in an extremely deformed form.

Kaguya (Child)

Serves as the judge in the brain (internal) battles.