Sugar Peace, also recognized as Sugar Peas, serves as a detective within the Shield Police Department under Inspector Greg Young. Highly motivated yet inexperienced, she possesses a fierce commitment to justice that manifests as intense preoccupation with cases; once concerned, she cannot focus elsewhere until resolution. Her effectiveness against Players—individuals wielding supernatural abilities granted by X-Playing Cards—is hampered by her own lack of such a card, fostering a somewhat naïve self-perception and low self-image.

Following Inspector Young's temporary incapacitation due to injuries, Sugar intensified her investigative efforts, laboring relentlessly to exhaustion in pursuit of conspiracies involving X-Playing Cards and covert organizations like High Card. Her tenacity emerged clearly during an independent investigation into Pinochle, a luxury car company acting as High Card's front, after social media footage of their activities vanished and colleagues dismissed her suspicions.

Later, amid escalating jurisdictional conflicts between police and High Card, Young's death marked increased vulnerability for central characters. Sugar pursued Prince Noah for Young's murder, Klondike mafia family ties, and an attempted assassination of Prince Louis. Her actions secured Noah's arrest and fueled public distrust toward Fourland's royal family, though at significant cost including multiple casualties. Post-crisis, she championed police authority over Player incidents, arresting High Card members under the conviction that law enforcement should manage such threats—despite the force's lack of Players.

Sugar Peace's journey traces a path from a self-doubting novice to a resolute investigator challenging systemic corruption and power struggles rooted in X-Playing Cards.