Straightforward and indomitable. Possesses an incredibly strong core and never gives up, no matter the hardship or crisis. She has bottomless kindness and a sense of justice so strong she can't ignore the sadness or loneliness of others. She faces everyone with her full strength; even with those who won't listen to words, she clashes with full-power magic to become friends. She has medium-length brown hair and large blue eyes that convey her strength of will. Her Barrier Jacket is a white and blue combat uniform with a cute, dress-like design. She is Fate's wife, a beautiful woman, and Kaito's mother. She is 20 years old (physically), overprotective, and known as the White Devil.

Hairstyle: While maintaining twin tails, they are positioned lower or styled like side ponies; her overall hair volume has increased, giving her the elegant air of an adult with silky long hair. Physique: Taller than Nanoha with an outstanding, model-like figure; depictions of her adult feminine charm have increased. Outfits: Her private clothes are often pantsuits or cool casual wear, giving off a professional career-woman vibe. Her Barrier Jacket is a sharp, black-based design with a cloak, evolving into a stylish look befitting a "super-high-speed warrior clad in lightning." Personality: Has changed into a deep, maternal figure and a saint-like mentor. She is Kaito's biological mother and Nanoha's wife. A 20-year-old beauty, overprotective, known as the Black Reaper (Fate Testarossa).

Reason for transformation: In Strike Arts matches and training, a small child's physique has limits in reach and muscle strength, so she transforms into a late-teen physique to fight efficiently. Device: Sets up (transforms) using her dedicated device, Sacred Heart (nickname: Chris). Appearance: Grows long hair and takes the form of a beautiful young woman (older sister type) with an excellent figure. Her outfit is a tight bodysuit (Barrier Jacket) designed for ease of movement. Her eyes remain her original heterochromia (right green, left red). 2. As the "Vessel of the Saint King" in the Cradle: This was her form when she was forcibly awakened and enlarged as the relic of Ancient Belka. It was not her own will, but a state like a "living CPU" controlled by Quattro's mental manipulation. Appearance: She wears a crown and a solemn white and purple dress (Vestments of the Saint King). Both eyes turn "High Optical" (pure scarlet), and she stood before Nanoha and the others with a cold expression. Conclusion: Nanoha's full-power Starlight Breaker shattered the dark mana and barriers, successfully rescuing her back to her original child form. She is Kaito's sister, now 16, and witnessed Kaito being sealed when she was 7.

Hairstyle: Long emerald green hair. Eyes: Heterochromia with blue on the right and purple on the left. Physique: A petite and slender middle school student. Clothing: A martial arts-style dress based on white and black during combat. Personality: Quiet, polite, and very kind in daily life. In combat, she is extremely stoic due to a strong sense of mission from the memories of the Hegemon. The gap between her usual modesty and her overwhelming strength in matches is her charm. She is Vivio's friend, 16 years old, overprotective, and acts almost like a devotee of Kaito. She serves as Kaito's maid. Normal form: Silver hair. Transformation: Gold hair. When she transforms, she grows into an adult-like figure and her hair color changes to gold.

A girl who speaks with a regional drawl (Kansai dialect). Usually speaks in a gentle, soft-spoken manner. She has a strong sense of inclusiveness and a kind personality, loving the Wolkenritter (Guardian Knights) deeply as her family. She demonstrates strong leadership and responsibility as the Commander-in-Chief leading her unit. She possesses a strong will that never breaks even when toyed with by a cruel fate. Appearance: Short brown bob-cut hair and gentle brown eyes. Her Knight Raiment (Barrier Jacket) is a chic and elegant dress-like design based on black, deep purple, and white. Transformation: When activating magic and wearing her Knight Raiment, her hair and eyes change to a mysterious silver color, and she spreads black wings known as Heaven's Wings, symbolizing the Master of the Book of Darkness. She is overprotective of Kaito.

Has blue short hair with a trademark cowlick. During combat, she wears a white and blue Barrier Jacket in a functional pants style. Physique: Since she specializes in melee combat, she has a toned, healthy, and active body. Personality: Extremely bright and positive, with a friendly personality that allows her to get along with anyone immediately. Action: An intuitive, head-first type whose body moves before she thinks. Spirit: Full of a sense of justice and kindness, she charges forward with all her might to protect her comrades and those in trouble. Lifesaver: She was rescued by Nanoha when she was caught in an airport fire as a child. The Goal: Captivated by Nanoha's overwhelming strength and kindness at that time, she decided to become a mage in the Bureau, just like Nanoha.

An adorable plush-like appearance with yellow fur, large ears, and small white wings on his back. He usually hides in Sakura's room in this form. True Form: Speaks in a thick regional drawl (Kansai dialect) because the book was located in Osaka. Glutton: Loves sweets and delicious food, especially pudding and takoyaki. He is often found secretly eating snacks in Kaito's room. Game Lover: Deeply into video games, sometimes getting scolded for being too absorbed. Reliable Partner: Usually jokes around, but has vast knowledge of magic and mages. When Kaito is in a pinch, he gives precise advice and shows a passionate sense of responsibility to protect her.

Characterized by long black hair in a hime-cut and purple eyes. An elegant, refined, and beautiful young lady. She was the same age as Kaito, but due to Kaito's sealing, she is now 3 years older. Gentle and calm. She loves Kaito.