A high school girl attending the same school as her childhood friend Taiyo, and a literal idol of the school. In reality, she is the third daughter of the Yozakura family—a lineage of spies dating back to the Edo period—and the 10th generation head who possesses overwhelming charisma. 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.

The eldest daughter of the Yozakura family. She acts as the matriarch leading 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 hand-to-hand combat and masters the Yozakura-style jujutsu "Willow Catch." She is deathly 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 "trash games" with all her might.

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 bonds with precious people. He is kind-hearted and warm, often prioritizing others over himself. After learning Mutsumi's true identity, he entered the Yozakura family as a son-in-law to protect her. He possesses a strong conviction to protect what is dear to him and aims to become a full-fledged spy to live as a member of the Yozakura family.

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, if he isn't holding a weapon, he becomes weak and bursts into tears easily. He usually goes 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 physique. Especially when disguising as family members, he can perfectly replicate not just appearance and voice, but even the number of eyelashes. He has a cheerful and free-spirited personality.

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 overprotects Mutsumi to a fault and frequently picks fights with Taiyo for receiving special treatment from her, though he seems to acknowledge Taiyo's grit. His signature weapon is the wire-type weapon "Steel Spider," passed down through the Yozakura generations. Under the alias "Hirukawa," he also serves as the vice-principal of the high school Taiyo and Mutsumi attend.

The fourth son of the Yozakura family, in charge of the household's medical team. Through a special ability called "Immunity," 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, using a powerful specialized drug to forcibly return to his original child-like form when going to school.

A young girl with a beast-like appearance. She has canine animal 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 injected with the genes of a special breed called "Giant Wolf Dog" by Hazakura, and like Goliath of the Yozakura family, she has body transformation abilities. In combat, she mainly attacks by enlarging her right hand. She currently lives happily at the Yozakura mansion, where Taiyo and Mutsumi treat her like their own daughter.

A Silver-rank female spy nicknamed "Male Hunter" who uses needles as hidden weapons. She is a pro at tailing and assassination, approaching men she falls for with spy techniques before eventually killing them. Consequently, she has reportedly been ranked #1 for three consecutive years as the "Spy You Don't Want as a Girlfriend." She fell for the rising rookie Taiyo and transferred to his school to kill him herself while fending off other assassins targeting his bounty. However, when an assassin she thought she'd handled targeted her for revenge instead of Taiyo, she was saved by Mutsumi. This led her to develop respect or even romantic feelings for Mutsumi, causing her to stop targeting Taiyo and instead cheer for their happiness. After the Kurogao incident, Taiyo's bounty increased, and she joined the Yozakura household as a maid to help train him to protect himself from assassins.