Shirley belongs to the new generation of Seven Knights at Granseed Academy, successors who bond with legendary heroes' souls to fight the resurgent cult of Physis. She possesses distinct green hair flowing to her waist and striking red eyes, typically attired in thigh-high boots, gloves, and a beret.

A vampire requiring human blood for sustenance, Shirley forms a close bond with her romantic partner Ellen, another Seven Knight, who voluntarily provides her own blood. This relationship becomes central to Shirley's growth. When Ellen nearly dies after using temporal magic to save Nemo, Shirley turns her into a vampire to preserve her life, forging a shared immortality that deepens their connection.

Shirley navigates complex interpersonal dynamics within the group. She briefly creates a perceived love triangle involving Nemo, prompting him to choose between dancing with her or Faria, though her true romantic commitment remains solely with Ellen. This subplot culminates in Shirley confronting Ellen for nearly sacrificing herself without considering Shirley's feelings, leading them to mutually promise eternal togetherness.

Her narrative arc, deeply intertwined with Ellen's, explores themes of mutual acceptance and commitment. Following the final battle against the cult leader Sophitia, Shirley reaffirms her role within the Seven Knights with her relationship firmly intact.