Nero Yuzurizaki is one of the four main protagonists of the Tantei Opera Milky Holmes franchise, appearing across multiple series including Futari wa Milky Holmes. She is a young detective-in-training and a member of the detective unit known as Milky Holmes, which operates under the guidance of Opera Kobayashi in the Yokohama District. Her name is derived from the famous fictional detective Nero Wolfe.

In terms of personality, Nero is an obnoxious and outspoken girl with a very large appetite, often seen eating ravenously or thinking about food. She speaks using the masculine personal pronoun boku, which contributes to her blunt and tomboyish manner of speaking. She is notably selfish and self-centered, frequently talking down to others while simultaneously indulging her own desires and greed. Despite these rough edges, she remains a loyal member of her team and is devoted to her friends when the situation truly calls for it. Her behavior is often that of a tough and rough detective girl who does not hesitate to speak her mind or act on her impulses.

As a member of Milky Holmes, Nero's primary motivation is to function as a detective and use her abilities to solve crimes and stop thieves. She is part of a group of four young girls who train at the Holmes Detective Academy, working to develop their supernatural powers known as Toys. Nero's specific Toy ability allows her to control machines using a small piece of metal, giving her a unique edge in investigations and confrontations that involve mechanical or electronic devices. This power is a key part of her role in the story, as she uses it to manipulate technology to assist her team during their cases.

Within her team, Nero interacts closely with her fellow Milky Holmes members: Sherlock Shellingford, Hercule Barton, and Cordelia Glauca. The group dynamic is characterized by a mix of camaraderie and chaos, with Nero often clashing with or teasing her teammates due to her selfish and blunt nature, but ultimately standing by them when they face challenges. In Futari wa Milky Holmes, which takes place two years after the earlier series, the story shifts focus to two new young girls, Alice and Kazumi, who form their own detective unit called Feathers after being inspired by Milky Holmes. Nero and the rest of Milky Holmes appear as established figures who serve as role models and occasional support for the new protagonists, though the main narrative centers on the Feathers duo rather than Nero herself.

Throughout the franchise, Nero does not undergo a dramatic transformation in personality, but she is consistently portrayed as a reliable if abrasive member of the team, balancing her selfish tendencies with moments of genuine dedication to her friends and her duties as a detective. Her notable abilities are centered on her Toy power to control machines, which she employs creatively in various situations, and her physical energy and appetite are also recurring traits that define her character. She is a recognizable and energetic presence within the Milky Holmes universe, representing a brash but capable detective who contributes to the group in her own distinct way.