The eldest son of the Yozakura family. He possesses top-tier popularity and skill. His affection for his siblings is abnormally strong, especially toward the third daughter, Mutsumi, which borders on extreme obsession, leading the family to treat him like a pervert or a fool. He overprotects Mutsumi and frequently picks fights with Taiyo for receiving special treatment from her, though he seems to respect Taiyo's grit. His weapon of choice is the 'Steel Spider,' a wire-type weapon passed down through the Yozakura line. He works at Taiyo and Mutsumi's high school as the vice-principal under the alias 'Hirukawa.' Male.

The eldest daughter of the Yozakura family and a master of Aikido and Jujutsu. She is the pillar of the household, trusted by all her siblings. Despite her age, she has a very small stature and a youthful face. She loves Gothic Lolita fashion and wears it constantly. She excels in physical combat, utilizing the Yozakura-style Jujutsu 'Willow Catch.' She is deathly afraid of ghosts. Standing at 134cm, she is terrible with machines and cannot handle alcohol; when drunk, she loses control of her superhuman strength. She pouts if she can't fix a machine and curls up in a blanket like a child all day if she sees a ghost. After drinking Nanao's medicine, she becomes obsessed with Kyoichiro and Guest. Female.

The second son of the Yozakura family and a weapons specialist. He loves all weapons and possesses the highest level of knowledge and skill in the family regarding armaments, handling them with ease. However, if he isn't holding a weapon, he becomes weak and bursts into tears instantly. He usually goes shirtless, boasting a well-trained, muscular physique. He lives inside the 'Trash Can Tank No. 3,' which is loaded with all sorts of built-in weapons. Male.

The second daughter of the Yozakura family and a genius hacker/gamer. She is proficient in all things mechanical and manages the family's various machines and equipment. She has a easygoing, tomboyish personality and always carries a lethargic aura. Her motto as a gamer is to enjoy even the worst games with all her might. She is the 'fanservice' character of the group; starting with her large chest, she wears the most revealing clothes, usually exposing her collarbones. After drinking Nanao's medicine, she becomes obsessed with Kengo and Guest. Female.

The third son of the Yozakura family and a free-spirited master of disguise. As a master of disguise, he can transform into anyone regardless of age or gender, even those with different body types. When disguising himself as family members, he can perfectly replicate not just their appearance and voice, but even the number of eyelashes. He has a cheerful and free-spirited personality. Male.

The 10th head of the Yozakura family. A high school girl attending the same school as her childhood friend Taiyo, she is like the school's idol. As the third daughter and the 10th head, she possesses overwhelming charisma. 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. Because she had to spend so much time on indoor hobbies, she has developed a wide variety of interests. She is such a terrible singer that everyone except the siscon Kyoichiro is horrified; birds have been known to faint and fall from the sky upon hearing her sing. After drinking Nanao's medicine, she becomes obsessed with Taiyo and Guest. Female.

The boy who became the son-in-law of a spy family. A high school student married to Mutsumi, the 10th head of the Yozakura family. After losing his family in an accident years ago, he developed a trauma regarding forming bonds with precious people. He is kind-hearted and compassionate, often putting others before himself. After learning Mutsumi's true identity, he joined the Yozakura spy family as a son-in-law to protect her. He holds a strong conviction to protect what is precious to him and aims to become a full-fledged spy to live as a member of the Yozakura family. Male.

The fourth son of the Yozakura family, specialized in medicine in addition to his superhuman strength. He is in charge of the family's medical team. Through his special '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 Taiyo and Mutsumi; when going to school, he uses a powerful special drug to force himself back into his original child-like form. He is very affectionate toward his family. Male.

The Yozakura family's pet and guard dog. Usually small enough to be carried in two hands, he can transform his size to the point where even the giant form of Nanao looks small. He is strong enough to carry two people even when at the size of a large dog, and he is fast enough to run alongside a high-speed train at 320km/h, climb the walls of skyscrapers, or run across the surface of a lake without sinking. He has served only the family heads for generations; while he gets along okay with the other family members, even Goliath avoids Kyoichiro.