TV-Series
Description
Queen, whose real name is Emerald Queen and who is also known as Diamond Queen, is one of the central characters in the anime Mysterious Joker. She is introduced as a childhood rival and friend of the phantom thieves Joker and Spade, and she becomes one of the series' main characters. She is a teenage girl with long blonde hair and yellow eyes.

Queen was born into a ruling family, as her parents governed the Duchy of Emerald. When she was still an infant, Professor Clover killed her parents. At the request of her dying mother, the master thief Silver Heart took her from the castle and raised her as his granddaughter. To protect her from assassination attempts, he kept her true lineage a secret. Queen grew up training as a phantom thief alongside Joker and Spade under Silver Heart's guidance. Years later, Professor Clover revealed her identity to her and manipulated her into believing that Silver Heart had murdered her parents and kidnapped her. As a result, she abandoned her training, swore revenge against Silver Heart and phantom thieves in general, and began working for Professor Clover, destroying treasures so that no one else could steal them.

In terms of personality, Queen is enthusiastic, bold, and energetic. She is bright and somewhat tomboyish, tends not to worry about small details, and is described as bad at cooking but skilled with blades. She prefers physical strength and direct action over clever schemes, which contrasts with the more strategic approaches of Joker and Spade. She has a strong sense of justice, which can sometimes make her pushy or meddlesome, and she has a short temper that causes her to become frustrated easily. During her training years, she was notably competitive and had a tendency to cry easily when things went wrong.

Queen's role in the story changes as the plot unfolds. She initially appears as an antagonist aligned with Professor Clover, using her grudge against phantom thieves to justify her destructive actions. Over time, the truth about her past comes to light, and she reconciles with Silver Heart and her childhood friends. After Joker tells her the full story of how she was adopted and why her identity was hidden, she completes her training and becomes a full-fledged phantom thief, taking her place alongside Joker and Spade.

Her key relationships center on Silver Heart, Joker, and Spade, as well as her companion, a talking dog named Roku, who serves as her closest assistant. Her connection with Joker and Spade develops from childhood friendship and rivalry into partnership. In later sequel material set years after the original story, she is depicted as having married Joker and as the mother of their son, though she has disappeared before the events of that continuation.

In terms of abilities, Queen is physically powerful and relies more on her own strength and wits than on gadgets. Her signature weapon is a diamond-bladed sword capable of cutting through nearly anything, including cars. She is also shown using playing cards in combat. Despite her straightforward style, she completes her full phantom thief training and proves herself a skilled and dependable thief.