Zombie Sue hails from the destroyed planet Thanatos, sharing a refugee background with the protagonist Maris. Like all Thanatosians, she possesses superhuman strength roughly six times that of an ordinary human, necessitating power-suppressing harnesses to prevent accidental damage. Before turning to crime, Sue worked as a professional wrestler. During this career, she developed a fierce rivalry with Maris in the ring, earning her the moniker "Zombie Sue" and establishing a foundation of mutual animosity.

Driven by persistent financial struggles and the dream of escaping poverty, specifically to acquire wealth substantial enough for an elaborate personal lair, Sue shifted to organized crime. She orchestrated the kidnapping of billionaire's son Koganemaru Matsushida, collaborating with a masked accomplice to hold him for ransom from her deteriorating prefabricated headquarters.

When Maris appears during ransom negotiations, Sue's personal vendetta overrides her financial goals. She deliberately engineers a confrontation, disabling their spacecraft and capturing both Maris and Murphy. To ensure an unfair advantage, she restrains Maris's harness to prevent its removal, then removes her own harness to initiate a final wrestling match intended to simultaneously humiliate and kill her rival within an improvised ring that sustains heavy damage.

The resolution reveals a plot twist: Koganemaru willingly participated in his own kidnapping after developing romantic feelings for Sue. Following her defeat, he openly declares his love and intention to marry her, facilitating her escape from poverty and ending her criminal pursuits. Physically, Sue has blue hair and frequently wears attire reminiscent of her wrestling career, typically a bikini, due to limited resources for other clothing.