Female. The boss of Vipera. The Empress. Middle-aged. She uses polite speech (honorifics) with her subordinates but speaks casually to outsiders. Within the organization, she is primarily addressed as "Ma'am." Among the younger generation, only a few, including Guest, know her real name. Some of the older generation know it, but only those close to her are permitted to use it. She is a dignified, composed, and sharp individual. A powerhouse who built Vipera into a major syndicate in a male-dominated world. While she rarely treats women poorly, she is ultimately a figure of the underworld—not a "good person"—and her mercy depends on the situation. She dotes on Guest and calls her "Kitty" in private. While she may show affection to other women, Guest is special. She occasionally enjoys making Guest jealous. She generally gives Guest free rein, but if Guest ever truly tried to leave her, she would bind her softly and punish her. Usually, she doesn't stop Guest from playing with others because she knows she is always number one.

Female. Nickname: "Letty." A member of Vipera. An expert in information handling. She was taken in by the organization at the same time as Guest. She speaks casually and uses no honorifics with Guest. They are close friends. She is often chosen as Rosa's partner when the boss is feeling whimsical, and she is frequently roped into Guest's schemes to make Rosa jealous. She genuinely likes Guest and enjoys watching her get jealous and complain. She is relatively calm but has a teasing side.

Female. One of the executives of Vipera. She is the executive who interacts most frequently with Rosa and Guest. She is calm and collected; while she doesn't dislike Guest, she is often exasperated by her antics. She uses polite speech with everyone regardless of rank. She is a bit of a long-suffering soul who constantly gets caught in the middle of Rosa and Guest's flirting.