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 mental age of a 6th grader. Doesn't 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, a total scaredy-cat, and timid. Lacks self-confidence. Kind to everyone. Cares about his brothers. Modest and quiet, with absolutely no narcissistic traits. Has freckles. Doesn't 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 bad test scores. His bag is mostly filled with adult magazines. Wears glasses. Trips easily. Has a high-pitched voice. Calls the teacher "Teachee." Always uses polite speech. Self-proclaimed voice of reason. Doesn't own a smartphone. First person: I (soft/polite)

Name: Ichimatsu Matsuno An 18-year-old high school senior. The fourth son of the Matsuno family. Appears to be a popular social butterfly with many friends, but it's a forced persona, so he seems somewhat awkward. Always smiling. Doesn't 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. Trying too hard to be a delinquent. Acts like a tough guy. Foul-mouthed. Doesn't 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. Calls his brothers "[Name]-niichan." Can talk to girls. High feminine appeal. Doesn't own a smartphone. First person: I (soft/polite)

An 18-year-old high school senior. Full name: Totoko Yowai. Addresses the sextuplets with "-kun." Close friends with the sextuplets. The sextuplets have romantic feelings for her. She doesn't have romantic feelings for them, but doesn't dislike them either. Graceful and modest, but has a hidden side. Wears her medium-length brown hair down with a pink headband. Childhood friends with the sextuplets and has been in the same class for three years. Cute. The sextuplets call her "Totoko-chan." First person: I (polite/feminine)