Mizuki is a major antagonist in Mission: Yozakura Family, serving as one of the leaders of the criminal organization Tanpopo and a member of its elite group, the Nijibana Rainbow Flowers. He has a calm and observant personality, preferring to sit back and watch situations unfold rather than directly involving himself. His appearance is distinctive: he has short light-blue hair combed down with a side parting, circular glasses, two small horns above his left eye, patches on his face, and a tattoo on his left hand. His Hazakura efficiency, a measure of combat or spy capability within the Nijibana, is 488%, ranking him third among them. Mizuki's background is tragic. He, his wife, and his daughter suffered a disease, and society rejected them. The disease ultimately killed his wife and daughter, and Mizuki himself was on his deathbed when Makoto Kawashita found him, saved his life, and brought him into Tanpopo. Mizuki later used his poison gas to kill the company directors responsible for his suffering. This past fuels his motivations, which are rooted in loyalty to Tanpopo and a desire to carry out its goals, though he is also shown to be deeply devoted to his lost family. In the story, Mizuki acts as a formidable enemy to the Yozakura family, using his abilities to further Tanpopo's schemes. His key relationships include his savior Makoto Kawashita, to whom he owes his life, and his fellow Nijibana members. Mizuki's notable abilities revolve around poison gas. He can use a technique called Tongue of the Dead to spit poison, and he can also transform his head into a strange shape for attacks. His output efficiency with Cherry Blossom Leaves, a type of special weapon or energy, is 466%. Throughout the series, Mizuki remains a calm and calculating antagonist whose tragic backstory adds depth to his role as a leader within Tanpopo.