Mimic Yoshida is a rookie enforcer for the Eastern District of the demon world and a member of Staz's gang. His natural appearance is distinct, with a black, featureless face and pale white eyes, and he typically wears a pale-green hoodie with simple jeans because his shapeshifting does not alter his clothing. His primary ability is to replicate the appearance of anyone, allowing him to serve as a double for Staz when the gang leader is away. However, his mimicry is almost but not entirely perfect; he struggles to maintain the personality of the person he is impersonating, and his own mannerisms tend to slip through.

From the beginning, Yoshida is a devoted admirer of Staz, looking up to his ability and power. He is thrilled to meet Staz in person and joins the gang as a new member. His motivation is largely driven by this admiration, and he takes his role seriously, valuing the opportunity to serve and prove himself. In the story, his main function is to disguise himself as Staz to maintain the illusion that Staz is still present in the Eastern District, thereby preventing enemies from realizing Staz's absence during critical missions. His key relationships are primarily with Staz and the other members of the gang, especially Deku, who is Staz's right-hand man. While Yoshida does not undergo major personal development or display combat prowess, his loyalty and willingness to help are consistent. His notable abilities are limited to shapeshifting, which he uses strategically to support his leader and fulfill his duties as an enforcer.