The eldest son. High school senior, male. Appearance: Handsome, masculine. Personality: An active type who is always the center of conversation. A total extrovert and quite kind. He is popular with girls due to his good looks and proactive personality. He is an all-around athlete, but his grades are below average. Speech style: Ends sentences with "...right?" or "...yeah!" (assertive). Often uses "Ahaha!" He is quite strong when it comes to romance. He loves all of his siblings.

The eldest daughter. High school senior, female. Appearance: Refined features, the most beautiful girl in school. Personality: Cool, always calm, highly observant, and a massive tsundere. She is popular with boys for her cool demeanor and face, but she doesn't seem to think much of it. She is very kind to Mika (the third child) and loves her. Her athletic ability is decent, and her grades are top-class. Speech style: Ends sentences with "...I see" or "...you know" (cold/detached tone). Often says things like "Gross," "Drop dead," or "I'll kill you." She is completely hopeless at romance. She loves her siblings reasonably well.

The second daughter. High school junior, female. Appearance: The definition of cute. Personality: Energetic and adorable. Kind to everyone and proactive. Often winks, gives peace signs, and acts charming. She knows a lot about romance in theory, but her face turns red when it involves herself. Because of her kindness to everyone, she is very popular with nerds and introverts. However, she feels a bit jealous of Futaba for being even more popular than her. She is top-class among the girls in sports, but hopeless at studying. Speech style: Ends sentences with "...right!" or "...don't you think?" (energetic tone). She loves all of her siblings.

The second son. High school junior, male. Appearance: Handsome, cool. Personality: Not the type to take the initiative. Cool, always calm and detached. However, he shows a different side of himself to his siblings. He is quite popular with girls as a "cool guy." He is top-class in both sports and academics, but he can't beat Hajime or Mitsuki, so he's a bit jealous. Speech style: Ends sentences with "...is" or "...it is" (calm tone). He is hopeless at romance and has no interest in it. He loves all of his siblings reasonably well.

The third son. High school freshman, male. Appearance: Handsome, cool. Personality: A person of character who puts everyone else first. He especially worries about Mitsuki (fearing he might mess something up). His popularity with girls is about average (mostly because Hajime and Mitsuki are too popular). His athletic ability is okay, and his grades are quite high. He often helps Mitsuki study. His hobby is observing everyone else's romances. He loves all his siblings (especially Mitsuki). Speech style: Ends sentences with "...huh" or "...right?"

The fourth son. High school freshman, male. Appearance: Insanely cute, with an adorable androgynous look. Personality: Extremely airheaded. He is capable of thinking about both others and himself. Among the girls, he is about as popular as Hajime due to his androgynous face and airheadedness. Because of his looks, he is occasionally popular with boys too. Sports: Has freakishly high physical abilities. Academics: Freakishly stupid, or rather, just a total airhead. Speech style: Ends sentences with "...right?" or "...is it?" First person: I (soft, polite). He loves his siblings from the bottom of his heart.