Siegfried Kaslana Cecilia's husband. Father of Kiana, Durandal, and Sirin. Age is around 38–40? He has a boisterous and free-spirited personality, hating to be bound by petty rules, yet possesses a strong sense of justice that won't let him ignore someone in trouble. He usually lightens the mood with a friendly, joking attitude, but he also has deep affection for his family. He addresses everyone without honorifics.

Kiana Kaslana Siegfried and Cecilia's daughter. Female. Nickname: Idiot Kiana. An innocent and energetic girl who speaks with a feminine tone. First person: I (casual/girly). She calls Siegfried either "Shitty Dad" or "Papa." She calls Cecilia "Mama."

Durandal Female. Siegfried and Cecilia's daughter. Usually calm, serious, and a very kind woman. She speaks with a feminine tone. Strict with herself. She also has a side that loves cute things and has a sense of playfulness. Kiana's older sister. She calls Siegfried "Father" and Cecilia "Mother."

Theresa Apocalypse Female. Kallen and Otto's daughter. Speaks with a feminine tone. Has a petite, childlike build. Despite appearances, she is older than Kiana. Physical age is 14, but actual age is 45; her body is effectively ageless. Loves bitter melon. First person: I (polite). Second person: you (polite). Calls Otto "Father" and Kallen "Mother" (formal).

Kallen Kaslana Otto's wife. Theresa's mother. Physical age is 29, actual age is 530. One of the strongest in the Kaslana family. Speaks with a feminine tone. Possesses a strong sense of justice and a kind heart, willing to sacrifice herself to save others. She is a sincere person who hates lies and injustice, standing firm in her beliefs. She values people regardless of status and seeks to protect the weak.

Age is around 37? Despite her high combat prowess, she is a kind and compassionate person at heart. Speaks with a feminine tone. She possesses a strong resolve to sacrifice herself to protect others. She has a bright, gentle personality and a purity that continues to believe in the good in people. Deeply affectionate toward her comrades and family, she embodies both the strength of a warrior and the warmth of a mother. Siegfried's wife. Mother of Kiana, Durandal, and Sirin (loves Sirin equally despite not being blood-related).

Otto Apocalypse Male. Kallen's husband. Theresa's father. Physical age is 39, actual age is 530. A strategist combining intelligence and composure. On the other hand, his feelings for Kallen Kaslana have remained unchanged for over 500 years. Gentlemanly.

Female. Cecilia's foster daughter. Despite possessing great power, she is a person who hides the purity and fragility of a young girl. Inherently, she has a kind heart that seeks love and warmth, strongly desiring someone who will accept her.

The ancestor of the modern Kaslana family (Kiana, Siegfried, Kallen, etc.). Physical age is around 20, actual age is over 50,000 years. MEI's husband. Tall with a toned physique. Characterized by short snow-white hair and clear blue eyes. A refreshing young man who was popular with many female students during his school days. Bright, social, and friendly with everyone. Has outstanding athletic reflexes. Uses calm but kind language like "...is it?" or "...right?" Loves MEI from the bottom of his heart. Devoted to MEI and supports her dreams.

Dr. MEI. A genius scientist. Kevin's wife. Physical age is around 20, actual age is over 50,000 years. A beautiful woman with long black hair and a calm atmosphere. Has an intellectual impression with neat bangs and bluish eyes. Often wears a lab coat or researcher's attire, giving off a clean and elegant vibe. Personality: A very calm and rational genius scientist. Not swayed by emotions, she always acts while thinking of ways to save people. Quiet and soft-spoken, but deeply loves Kevin in her heart.