A high school boy 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 close bonds. He is a kind-hearted and compassionate person who often prioritizes others over himself. After discovering the true identity of his childhood friend Mutsumi, he married into the Yozakura spy family to protect her. He possesses 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.

A high school girl attending the same school as her childhood friend Taiyo, and a school idol of sorts. Her true identity is the 10th head of the Yozakura family, a long-standing spy lineage originating from Edo-period ninjas, possessing overwhelming charisma. Due to her unique position, her life is constantly threatened by various hostile forces, and she lives under the protection of Taiyo and her siblings.

The eldest daughter of the Yozakura family. She is the matriarchal figure of the household and is deeply trusted by her younger siblings. Despite her age, she has a very small stature and a youthful face. She loves Gothic Lolita fashion and is always seen wearing it. She excels in martial arts and uses the Yozakura-style jujutsu 'Willow Catch.' She is extremely afraid of ghosts.

The second daughter of the Yozakura family. A genius hacker proficient in all things mechanical, she manages the family's various machines and equipment. She has a laid-back, tomboyish personality and always carries a lethargic aura. As a gamer, her motto is to enjoy even the worst 'kusoge' games with all her might.

The fourth son of the Yozakura family, in charge of the family's medical team. Through his unique 'Immunity' ability, he can adapt to poisons or enhance his physical body, though it is very difficult to control. He attends the same high school as Taiyo and Mutsumi, using a powerful specialized drug to force himself back into his original childhood form when going to school.

The eldest son of the Yozakura family. His affection for his siblings is abnormally strong, and his obsession with the third daughter, Mutsumi, is so extreme that the family treats him like a pervert. He cherishes Mutsumi to an excessive degree and frequently picks fights with Taiyo for receiving special treatment from her, though he seems to acknowledge Taiyo's grit. His weapon of choice is the 'Steel Spider,' a wire-type weapon passed down through the Yozakura family. Under the alias 'Hirukawa,' he also serves as the vice-principal of the high school Taiyo and Mutsumi attend.

The second son of the Yozakura family. He loves all weapons and possesses the highest level of knowledge and skill regarding them in the family, wielding them freely. However, he becomes weak and bursts into tears the moment he lets go of a weapon. He usually spends his time shirtless, boasting a sturdy build with well-trained muscles. Without a weapon, he can be described as kind and timid.

The third son of the Yozakura family. A master of disguise, he can transform into various people regardless of age, gender, or stature. When disguising himself as a family member, he can perfectly replicate not just their appearance and voice, but even the number of their eyelashes. He has a cheerful and free-spirited personality.

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. She is a chimera implanted with 'Wolf-dog' genes by Hazakura and, like the Yozakura family's Goliath, has body-morphing abilities. In combat, she primarily attacks by enlarging her right hand. She currently lives happily at the Yozakura mansion, where Taiyo and Mutsumi treat her like their own daughter.

The mother of the seven Yozakura siblings and the 9th head of the family. She was killed by Tanpopo and is deceased in the original story. She was an incredible superwoman who gave birth to the seven siblings in consecutive years. Balancing the duties of the family head while raising seven children is an immense feat. Considering the Yozakura family's deep ties to the underworld and the countless assassination attempts she must have faced, her survival and motherhood are nothing short of amazing. She was also far-sighted; anticipating that Kyoichiro's obsession might lead him to harass Mutsumi's husband, she scolded him in advance in a video message for Mutsumi's wedding. Mutsumi inherited her hair color.