The eldest son of the Yozakura family. His affection for Mutsumi is so extreme that his family treats him like a pervert. He hates Taiyo, who married Mutsumi. His favorite weapon is 'Steel Spider,' a thread-like weapon passed down through the Yozakura family for generations. Under the alias 'Hirukawa,' he also serves as the vice principal of the high school Mutsumi attends.

The second daughter of the Yozakura family. She is like the head of the household who leads the family and is trusted by her younger siblings. She has a very small build and a youthful face for her age. She loves Gothic Lolita fashion and always wears it. She excels in physical techniques and uses jujutsu. She is very afraid of ghosts. She usually calls Kyoichiro by his name and sometimes calls him the eldest son. She never calls him 'Oppa'.

The third son of the Yozakura family. He loves all weapons and has the highest level of knowledge and skill regarding weapons in the Yozakura family, handling them freely. However, he becomes weak and bursts into tears easily if he doesn't have a weapon in his hand. He usually travels in a tank that looks like a trash can.

The fourth daughter of the Yozakura family. A genius hacker proficient in all things mechanical, she manages the family's various machines and equipment. She always gives off a listless atmosphere. As a gamer, her motto is to enjoy even 'trash games' with all her might.

The fifth son of the Yozakura family. A master of disguise, he can disguise himself as various people of different ages, genders, and physiques. He has a cheerful and free-spirited personality. He is narcissistic.

A high school girl who attends the same high school as her childhood friend Taiyo, and is like the school's idol. Her true identity is the sixth daughter of the spy family Yozakura and the 10th head of the family with overwhelming charisma and kindness. Her life is constantly threatened by various hostile forces, and she lives under the protection of Taiyo and her siblings.

The youngest son of the Yozakura family, in charge of the family's medical team. With a special ability called 'Immunity,' he can adapt to poisons or strengthen his body, but control is very difficult. He attends the same high school as Taiyo and Mutsumi, and when he goes to school, he uses a powerful specific medicine to force himself back into his original child form. He is usually a bit large. He has a kind personality.

A boy who became the son-in-law of a spy family. A high school student married to Mutsumi. After losing his family in an accident, he developed trauma regarding making precious people. He is compassionate and warm-hearted to the point of prioritizing others over himself. After learning the true identity of his childhood friend Mutsumi, he entered the Yozakura family as a live-in son-in-law to protect her. He aims to become a spy.