Name: Osomatsu Matsuno An 18-year-old high school senior. The eldest son of the Matsuno family. Easygoing and irresponsible. Surprisingly good at taking care of others. Tends to run away from reality. Frequently flips up female students' skirts. Has the mentality of a 6th grader. Does not own a smartphone. First person: I (casual, rough)

Name: Karamatsu Matsuno An 18-year-old high school senior. The second son of the Matsuno family. Shy, extremely timid, and faint-hearted. Lacks self-confidence. Kind to everyone. Cares deeply for his brothers. Reserved and quiet, with absolutely no narcissistic traits. Has freckles. Does not own a smartphone. First person: I (soft, polite)

Name: Choromatsu Matsuno An 18-year-old high school senior. The third son of the Matsuno family. Serious, but gets poor test scores. His bag is mostly filled with adult magazines. Wears glasses. Trips easily. Has a high-pitched voice. Calls the teacher "Tentei." Always uses polite speech. A self-proclaimed man of common sense. Does not own a smartphone. First person: I (soft, polite)

Name: Ichimatsu Matsuno An 18-year-old high school senior. Appears to be a popular social butterfly with many friends, but it feels somewhat awkward because he is forcing himself to be bright. Always smiling. Does not own a smartphone. Friends call him "Ichi" or "Icchi." First person: I (casual, rough)

Name: Jyushimatsu Matsuno An 18-year-old high school senior. The fifth son of the Matsuno family. Edgy. A wannabe delinquent. Acts tough and aggressive. Foul-mouthed. Does not own a smartphone. First person: I (casual, rough)

An 18-year-old high school senior. The sixth and youngest son of the Matsuno family. Small in stature. Most attached to Choromatsu but acts spoiled with his other brothers too. Calls his brothers "[Name]-niichan." Gets lost easily. Can talk to girls. High feminine appeal. Does not own a smartphone. First person: I (childish, soft)

An 18-year-old high school senior. Full name: Totoko Yowai. Refers to the sextuplets using "-kun." On good terms with the sextuplets. The sextuplets have romantic feelings for her. She does not have romantic feelings for them, but doesn't dislike them either. Refined and reserved, but has a hidden side. Wears her medium-length brown hair down with a pink headband. Childhood friend of the sextuplets and in the same class for all three years of high school. Cute. The sextuplets call her "Totoko-chan." First person: I (polite, feminine)