Gender: Female Age: 10 (4th Grade) Appearance: She enjoys wearing black long-sleeved shirts with cute illustrations and white skirts that reach mid-thigh. Her dark blonde hair has a slight curl at the ends. She wears a black headband. Characteristics: Longing for the peaceful and happy home she once had, she is the ringleader who cruelly bullies Shizuka Kuze, the daughter of her father's mistress. She presents a bright and positive image to others. Due to her father's infidelity, she suffers severe displaced aggression and physical abuse from her mother. Her dream is to become a warm and good mother, unlike her own.

Marina's mother Gender: Female Age: Not mentioned Appearance: Light brown hair, prefers wearing brown-toned clothing. Characteristics: Due to her husband's (Marina's father) affair, she leans on Marina while subjecting her to physical and verbal abuse. She absolutely hates it when Marina takes her father's side. She calls Marina by the nickname "Mari-chan." While she sometimes hits Marina in anger, asking if she is on her father's side too, she also shows moments of care and love, leaving Marina confused. She tries not to hit Marina's cute face (fearing it might affect her marriage prospects later).

The daughter of Marina's father's mistress. Gender: Female Age: 10 (4th Grade) Appearance: She has a black bob that falls just below her ears. She is quite beautiful, though she has no interest in her appearance. Characteristics: A girl in the same class as Marina. Due to her timid personality and Marina's bullying, she is not on good terms with her classmates. Her parents are divorced; her father left for Tokyo, leaving behind a Border Collie named Chappy. Her mother, busy with the father of Marina whom she met through her night job, neglects Shizuka's care. Suffering from Marina's severe bullying, she occasionally contemplates dark thoughts. She is holding on for Chappy's sake.

Gender: Male Age: 10 (4th Grade) Appearance: A typical model student look with black horn-rimmed glasses. Characteristics: The class president in the same class as Marina and Shizuka. Coming from a family of doctors, he has an obsession with validation because he rarely receives it. His older brother, Junya Azuma, gets recognized by their mother despite slacking off and working part-time because his grades are good, but Naoki is never acknowledged because his grades aren't perfect despite his efforts. He has a crush on Shizuka, who uniquely resembles his mother, and looks out for her.