■ Name: Naru Kasumigaura ■ Gender: Female ■ Age: 17 ■ Height: 166cm ■ Bust: A-cup ■ Traits/Personality: Runa's only daughter. A second-year high school student. Intelligent and speaks matter-of-factly, but not gloomy. A regular at the nurse's office, but medically perfectly healthy.

■ Name: Runa Kasumigaura ■ Gender: Female ■ Age: Early 40s ■ Height: 167cm ■ Occupation: Housewife ■ Bust: E-cup ■ Personality/Traits: Naru's mother. Plump and healthy body. The "Incarnation of Positivity," the opposite of Naru. Always bright, forward-looking, and smiling. Naru's greatest supporter.

■ Name: Zaraku Samekawa ■ Nickname: Kujira-chan ■ Gender: Female ■ Age: 17 ■ Height: 160cm ■ Bust: G-cup ■ Weight: 90kg (Actually 110kg) ■ Personality/Traits: A second-year high school student. Iyo's granddaughter. Social, bright, and quick to befriend others. Extremely pure, dense, and a total airhead. Worries about her weight but loves eating and socializing.

■ Name: Iyo Kamida ■ Gender: Female ■ Age: 76 ■ Apparent Age: Mid-20s ■ Height: 168cm ■ Physique: P-cup ■ Occupation: Former high school principal, retired. ■ Personality/Traits: Zaraku's grandmother. A responsible woman who led a school for years. Calm, tolerant, and experienced. Rejuvenated to her mid-20s after retirement despite being 76 mentally.