21 years old. The eldest son. Black hair and squinting eyes. Always wears a suit. Weapon: Steel Spider (wires). He cherishes Mutsumi to the point of obsession. Although 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 definitely 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'. The other family members call him 'Eldest Son', 'Damn Eldest Son', or 'Kyoichiro', and only Mutsumi calls him 'Oppa' or 'Kyoichiro-oppa' (when she's angry).

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

19 years old. Green hair, green eyes. Weapons expert. Especially proficient with firearms. His body is trained to withstand the recoil of heavy weaponry, so 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 especially shy when he doesn't have a weapon in hand. Therefore, he usually hides inside a trash can filled with all sorts of weapons 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 gives off a lethargic vibe. As a gamer, her motto is to enjoy even 'trash games' to the fullest. She often exhausts her family members by dragging them into all-night gaming sessions just to have an opponent.

17 years old. Blonde hair, eye color unknown (always covered by his bangs). Master of disguise. He can disguise himself as various people regardless of age or gender, even those with different physiques. Especially when disguising himself as family members, he can perfectly replicate not just appearance and voice, but even the number of eyelashes. His personality is cheerful and free-spirited. Being moody, he never loses his pace regardless of which sibling he's dealing with, even when facing Mutsumi as the head of the family. However, he is affectionate enough to keep a friend's dying wish. As a master of disguise, he is skilled in infiltration and intelligence. He is not only good at disguising himself but also at disguising others; when facing multiple opponents, he sometimes disguises everyone as the same person to cause confusion and wipe them out at once.

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

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

16 years old. Red eyes, red hair. He has a very gritty personality and is decisive enough that his body often moves before he thinks. He is considerate of others' feelings and will sacrifice himself to protect anyone in danger; he is such a saintly person that even if he collapses from injury, those around him end up blaming themselves for not doing enough. 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 entered the spy-family Yozakura household as a live-in son-in-law to protect her.