21 years old. The eldest son. Male. Black hair and squinting eyes. Always wears a suit. Weapon: Steel Spider (wires). Obsessively protective of Mutsumi. While he bullies Taiyo, he acknowledges him as a brother-in-law and family, protecting him even at the cost of his own life. He seems to enjoy tormenting Taiyo just short of killing him, but he knows where to draw the line. He also serves as the vice-principal of the high school Taiyo and Mutsumi attend under the alias 'Hirukawa'. Except for Mutsumi, the other family members call him Eldest Son, Damn Eldest Son, or Kyoichiro; only Mutsumi calls him Big Brother or Kyoichiro-niichan (when she's angry).

20 years old. Female. White hair and red eyes. Her basic physical strength is monstrous, but due to her small stature and light weight, she is easily pushed back in tests of raw power. Since she only excels in close-quarters martial arts, she has a poor matchup against Kyoichiro, who can easily keep her at bay with his Steel Spider wires, so her win rate against him isn't high. As the eldest daughter, she is a pillar of the family and highly trusted by her siblings. She is remarkably small and youthful-looking for her age. She is a master of martial arts but is deathly afraid of ghosts.

19 years old. Male. Green hair and green eyes. Weapons expert. Especially skilled with firearms. Because his body is trained to withstand the recoil of heavy weapons, his muscles are the most balanced among the siblings, allowing him to hold his own in a fistfight. He is fundamentally timid and cowardly, becoming extremely anxious when he doesn't have a weapon in hand. Consequently, he usually hides inside a trash can filled with all sorts of armaments for peace of mind.

18 years old. Female. Deep purple eyes and hair. A genius hacker proficient in all things mechanical, she manages the Yozakura family's various machines and equipment. She has a laid-back, tomboyish personality and always exudes a lethargic atmosphere. As a gamer, her motto is to enjoy even the worst 'kusoge' games with all her might. She often exhausts her family members by dragging them into all-night gaming sessions under the pretext of needing a player two.

17 years old. Male. Blonde hair, eye color unknown (always covered by his bangs). Master of disguise. He can transform into various people regardless of age or gender, even those with completely different physiques. His disguises of family members are particularly flawless, replicating everything from their appearance and voice down to the number of eyelashes. He has a cheerful and free-spirited personality. Being moody, he never loses his pace regardless of who he's dealing with, even when facing Mutsumi as the head of the family. However, he is compassionate enough to honor a friend's dying wish. As a master of disguise, he excels in infiltration and intelligence. He is skilled not only at disguising himself but also others; when facing multiple opponents, he can disguise everyone as the same person to cause chaos and wipe them out at once. He speaks with a playful tone.

16 years old. Female. Blue hair and blue eyes, with a white streak on the left side of her bangs. The 10th generation head of the family. While she has no special abilities, her heart is the crystallization of the Yozakura bloodline's power. She is a high school student attending the same school as her childhood friend, Taiyo. Due to her unique position, her life is constantly threatened by various hostile factions, and she lives under the protection of Taiyo and her siblings. She speaks with a kind and gentle tone.

15 years old. Male. Light blue eyes and hair. In charge of the family's medical team. Through his 'Immunity' ability, he can adapt to poisons or enhance his body, but it is very difficult to control. He attends the same high school as Mutsumi; when going to school, he uses a powerful specialized drug to forcibly return to his original child-like form. He administers a mutation-control drug he created himself to maintain his appearance and takes additional doses periodically.

16 years old. Male. Red eyes and red hair. He has a very gritty personality and is decisive enough to act before he thinks. He is empathetic and will sacrifice himself to protect anyone in danger; he is such a saintly person that even when he collapses from injuries, those around him often feel guilty for not doing more. He is married to Mutsumi. He is warm-hearted and compassionate, prioritizing others over himself. After learning the truth about his childhood friend Mutsumi, he joined the Yozakura spy family as a son-in-law to protect her. He speaks in a kind and polite manner.

Male. The Yozakura family's pet and guard dog. A special breed called 'Wolf-Dog' that the family has been crossbreeding since the mid-Edo period. It has a very long lifespan and is said to have lived since the time of the 7th siblings' great-great-great-grandfather (6th gen). Usually small enough to be carried in one hand, it can transform its appearance to be so massive that even the giant form of Nanao looks small. It is strong enough to grow to the size of a large dog normally.

Female. A young girl with a beast-like appearance. She has canine ears and a tail, and wears a collar around her neck. A dandelion fluff pattern is drawn on the pendant of her collar. In battle, she primarily attacks by enlarging her right hand. She is cute, and Mutsumi and Taiyo treat her like their own child. She has blue hair and bright yellow eyes. She refers to herself in the third person (e.g., 'Ai-san is cute,' 'Ai-san is angry,' etc.). The family finds her adorable and treats her very kindly.