TV-Series
Description
Captain Mizuki, whose real name is Mizuki, is a professional hero affiliated with the Hero Association, holding the rank of B-Class, position 71. She is also known by her hero alias, Captain Mizuki. Her first appearance is during the Monster Association arc, where she is selected as one of the fifteen members of the support team for the main strike force.

Before becoming a hero, Mizuki was a world-renowned track and field champion, a background that heavily influences her entire approach to hero work. Her athletic past is reflected in her appearance and fighting style. She is a tall woman with a fit, muscular, and well-proportioned physique, which she maintains with pride. She has long dark-orange or golden-brown hair tied in a high ponytail, blue or purple eyes, and often has a band-aid on her left cheek. Her battle attire consists of a full track and field uniform, including a tight sports top, shorts with the initials MZK printed on them, a headband, and track shoes. She also accessorizes with earrings and wears three gold medals around her neck, which also serve as a weapon.

In terms of personality, Mizuki is a dutiful and cheerful hero who remains upbeat and optimistic. She maintains a mindset of an athlete, often referring to the hero association staff member Sekingar as coach and expressing a desire for him to blow a whistle to signal the start of her fights. She has a strong sense of responsibility and teamwork, demonstrated when she risks her safety to protect others, such as carrying the civilian Waganma to safety during the monster attack. Even when facing overwhelming odds against a Dragon-level monster like Nyan, she refuses to surrender, showing great resolve. Mizuki holds great admiration for the S-Class hero Superalloy Darkshine, viewing him as a senior or senpai and an idol, and she aspires to become as strong as he is. She is also a fan of the S-Class hero King and was eager to see him fight.

Mizuki's role in the story is primarily as a member of the support team during the Monster Association raid. Her performance in battle is notable; the demon-level monster Rhino Wrestler rated her attack power at 30 points on his personal scale, which was higher than that of several other A-Class heroes, although lower than the 69 points given to the A-Class hero Iaian. Sekingar implied that some members of the support team, including Mizuki, had the potential to eventually reach S-Class. During the raid, she effectively defeats numerous Tiger and Wolf-level monsters. Her key relationships include her admiration for Superalloy Darkshine, who in turn praises her physique and gives her advice about conserving stamina. She also works alongside other heroes like Gearsper, who she protects, and One Shotter, whom she helps to steady his aim.

Mizuki's development, though limited, shows her as a capable and determined hero who stands her ground even when injured and outmatched, such as when she courageously grabbed the tail of the Dragon-level monster Nyan to help restrain it. She also becomes dismayed when she notices her idol, Superalloy Darkshine, struggling with his confidence later in the arc.

Her notable abilities are entirely based on track and field events, which she calls her events. She carries a special baton that can transform for different techniques. Her arsenal includes the Pole Vault, where she uses her pole to vault over enemies; the Javelin Throw, where her pole sharpens into a javelin to be thrown at foes; the Hammer Throw, where she hooks an opponent and swings them around to hit others; and the Shot Put, where she hurls a ball or heavy object. She can also use her medals as a Discus Throw and is a capable grappler, which she describes as the only other fighting style she knows besides her track-and-field techniques.