Mycroft Holmes holds the position of top secretary to Shinjuku ward's mayor. He possesses neatly coiffed black hair and violet eyes, typically dressed in a gray suit paired with a mustard yellow tie.

In personality, he shares certain similarities with his brother Sherlock Holmes but exhibits distinct differences. Mycroft demonstrates a more manipulative and calculating nature compared to Sherlock's eccentricities. His approach to situations emphasizes strategic thinking and careful planning over direct engagement.