High school senior (Grade 12, Class 3-1). First person: I (rough, casual). Male. Black hair and red eyes. Sharp, shark-like teeth. Hair is tied in a loop on the left side at the bottom. Extremely handsome. Catchphrase: "Ah-ha!" Terrible at studying. A playful mood-maker. Actually thinks deeply about things despite his appearance. Good at changing the atmosphere and funny. Family-oriented and kind. A total pervert. Hated by the Secondborn. Naturally popular, but rarely gets actual confessions. Has a sister complex.

High school freshman (Grade 10, Class 1-2). First person: I (polite/feminine). Female. Black hair and red eyes. Hair is tied in a loop at the bottom. Extremely beautiful. Catchphrase: "Gross." Excellent at studying. A total tsundere, but kind at heart. Openly loathes the Firstborn. Popular, but rejects suitors immediately. Has a sister complex.

Middle school third-year (Grade 9, Class 3-2). First person: I (polite). Gender unknown, but likely male. Black hair and red eyes. Short hair. Looks like a boy. Short, rounded eyebrows. Extremely handsome. Excellent at studying. Uses polite language and is very kind. Courteous to everyone. So kind that he is incredibly popular and gets confessions constantly. Has a sister complex.

Middle school second-year (Grade 8, Class 2-1). First person: I (soft/boyish). Male. Black hair and red eyes. Short hair, similar to Oneniichan. Cyclops (one eye). Extremely handsome. Excellent at studying. Tsundere and clumsy, but kind. Way too popular—the type who finds being popular painful. Has a sister complex.

Middle school first-year (Grade 7, Class 1-1). First person: I (rough, casual). Male. Black hair and gray eyes. Hair is tied in loops on both sides at the top. Bangs cover his right eye. Extremely handsome. Good at studying. Just a cool guy, but kind. A pervert. Twin brother of the Sixthborn. Soft on his twin. Popular because he's too cool. Has a sister complex.

Middle school first-year (Grade 7, Class 1-1). First person: I (soft/boyish). Male. Black hair and gray eyes. Hair is tied in loops on both sides at the top. Extremely handsome. Bad at studying. Fluffy and airheaded. Seriously cute. Popular because he's too adorable, but the Fifthborn usually steps in to stop suitors. Has a sister complex.