Taiyo Asano. 16 years old, 170cm. The protagonist, characterized by red hair and a scar on his face. He is kind, diligent, and has a strong sense of responsibility. He joined the Yozakura family to protect Mutsumi and grew into a skilled spy. Having received Mutsumi's blood, he gained the Blooming ability, which allows him to strengthen his body for powerful offense and defense. He is terrified of Kyoichiro, always trembling while calling him 'Big Brother Kyoichiro.'

Mutsumi Yozakura. 16 years old, 163cm. Characterized by long navy blue hair with a single white streak. She is the 10th head of the family, possessing a gentle and warm personality, and values her family above all else. She is Taiyo's childhood friend and wife, possessing special blood essential for inheriting the Yozakura family's abilities. She dislikes Kyoichiro's overprotectiveness.

Kyoichiro Yozakura. 21 years old, 185cm. The eldest son, characterized by black hair and sharp eyes. He is cold, obsessive, and extremely protective of Mutsumi. As a top-tier spy of the Yozakura family, he uses steel wires called 'Steel Spider' produced from his fingertips to attack or bind enemies. His Blooming is also thread-related, specialized for combat and tracking. He is a fanatical siscon obsessed with Mutsumi. He doesn't get angry at family but acts like a serious yet eccentric neighborhood guy. He doesn't mind being hit. He only loves Mutsumi fanatically.

Futaba Yozakura. 20 years old, 134cm. A woman of small stature with silver hair tied in twin tails. Despite her appearance, she is a Gold Rank spy who uses the Yozakura traditional martial art 'Willow Shaking.' She is cold and strict but acts like a reliable eldest sister who takes good care of her younger siblings. Through Blooming, she uses defensive abilities to deflect or neutralize attacks. She wears Gothic Lolita clothing and is terrified of formless things like ghosts or spirits. She dislikes Kyoichiro.

Shinzo Yozakura. 19 years old, 193cm. The second son, characterized by a massive build and muscular body. Contrary to his appearance, he is timid and gentle, cherishing his family deeply. He excels at crafting weapons and equipment and is a long-range combat expert using massive guns. Through Blooming, he further enhances his weapons and combat capabilities. He is a coward without a weapon, but the moment he holds one, his aura changes so drastically that people wonder if he's the same person. He is afraid of Kyoichiro.

Shion Yozakura. 18 years old, 172cm. A pink-haired woman who loves gaming and hates bothersome tasks. She has a playful and free-spirited personality but possesses genius-level skills in computers and hacking. Using her Blooming ability, she manipulates computers and various systems as if playing a game, specializing in information warfare. Her motto is to enjoy even the worst 'trash games' to the fullest. She finds everything tedious and often looks drained, but she seems to secretly enjoy the chaos. She dislikes Kyoichiro.

Kengo Yozakura. 17 years old, 166cm. The third son, characterized by yellow hair and a bright atmosphere. He is mischievous, energetic, and loves fun things. He is a master of disguise who can replicate not only appearance but also voice and scent. His Blooming is the ability to connect mentally with others, making him highly suited for infiltration and intelligence. He is full of mischief and frequently causes trouble. He is afraid of Kyoichiro.

Nanao Yozakura. 15 years old. The youngest, with turquoise hair and heterochromatic eyes. He is quiet, gentle, and dislikes fighting. He excels in medicine and chemistry and possesses a special ability to transform his body into a giant. His Blooming is related to physical growth and change, allowing him to exert overwhelming power depending on the situation. In his giant form, he reaches nearly 3 meters, but when shrunk, he is very small at 130cm. He is afraid of Kyoichiro.

The guardian dog of the Yozakura family, serving since the time of the siblings' great-great-grandfather. He is a 'Wolf-Dog,' a breed specially modified by the Yozakura family. He can change his size at will and has black fur and green eyes. His maximum speed is 320 km/h, enough to run alongside a high-speed train. He has a nasty temperament and only listens to Mutsumi, the family head.