Mutsumi Yozakura is the current head of the tenth generation of the Yozakura spy family. She is the youngest daughter and sixth child of the family, and she becomes the wife of her childhood friend and the series’ main protagonist, Taiyo Asano. Mutsumi has a petite build, fair skin, soft navy‑blue eyes, and long dark navy‑blue hair that reaches her waist, styled in a hime cut with shoulder‑length strands framing her face. A prominent white streak in her hair is a lasting mark from a childhood abduction by the criminal group Tanpopo, during which her late mother’s roots were implanted in her body.

Mutsumi was raised in a relatively normal environment to gain knowledge of the outside world, separate from the spy industry. As a result, she became close friends with her neighbor Taiyo Asano, though she never revealed her family’s true nature to him. In their first year of high school, after Taiyo’s life was threatened by her overprotective eldest brother Kyoichiro, Mutsumi married Taiyo to protect him under the family rule that prohibits killing relatives. Their relationship is built on genuine love and mutual support; each is willing to give their life for the other.

Unlike her siblings, Mutsumi possesses no superhuman abilities. Instead, her exceptional leadership, sharp decision‑making, and natural charm allow her to guide and unite her wild and strong‑willed siblings. She is the emotional anchor of the Yozakura household, often acting as a source of reason and warmth during crises. She takes on domestic responsibilities, including cooking, and prepares meals that can aid the family’s spy missions. Her presence as the family head is crucial because she is expected to bear the next generation of superhuman children, making her a prime target for many enemies.

Mutsumi’s personality is characterized by kindness, resilience, and quiet determination. She is unfailingly supportive of Taiyo’s efforts to become a capable spy, reassuring him when he feels inadequate. She also shows unwavering resolve when her family’s safety or memories are threatened, declaring that neither her family nor the memories she shares with loved ones will ever disappear. Over the course of the story, Mutsumi grows from a childhood friend into a confident leader and devoted wife, balancing her role as the family’s heart with the dangers of the spy world. Her most notable abilities are her outstanding leadership and her capacity to inspire loyalty and trust in those around her.