Sonya belongs to the Midnight Panthers, a trio serving as popular singers by day and covert assassins by night. She sports dark hair and a buxom physique. Her signature assassination technique involves seducing targets, then utilizing her hair – capable of controlled growth, retraction, and enhanced resistance – to strangle them. This method exemplifies the group's pattern: intimate encounters followed by execution.

She operates alongside fellow members Kei and Lou, directed by an old hag manager coordinating their activities. The trio functions within a post-apocalyptic fantasy setting, leveraging their musical performances as cover for clandestine operations. Sonya's personality reflects the team's aggressive, sexually overt mission tactics, favoring a direct approach to seduction.

Her background remains undefined beyond her role in the group's activities. She consistently undertakes missions assigned by their manager, including a significant operation targeting a despotic king. While this mission holds personal significance for Lou, Sonya approaches it purely as a professional assignment. Her role within the team centers on tactical execution, not leadership or strategy. No substantial character development or evolution is documented across official media.