The evil and psychotic Dr. Von Reichter, a member of the SS and the Nazi party, is an expert in genetic engineering. He initially began his work in concentration camps during World War II, implanting cybernetic organs in the bodies of dead prisoners in an attempt to bring them back to life to serve in the Führer's army. However, the Allied forces intervened to defeat the Nazis, so he fled to South America where he once again continued his sinister experiments.
From one of his experiments emerged the Cyber Series — artificial humanoids possessing superhuman strength and agility. But something was amiss: The 5000 original Cybers, engineered to be the perfect servants, mimicked human emotions too closely, displaying free will of their own. When they began disobeying their creator, Von Reichter ordered all of the Cyber Series to be destroyed. By this time, Cyber-29 had already died in a playtime accident when he fell from a tree (a cliff in the animated series), but Von Reichter managed to transfer the dead child's brain into the body of a panther to be reborn as Data-7. Cyber-6 was the only true Cyber to survive the massacre, escaping with the help of a black slave who hid her away in a fishing village. When the slave was later interrogated and killed by Von Reichter, Cybersix escaped once again and made her way to the fictitious city of Meridiana, where she adopted the identity of a boy killed in a car wreck, Adrian Seidelman, and now battles her evil creator and his minions.
Like all of Von Reichter's creations, Cybersix depends on a mysterious life-giving fluid called "Sustenance". When her supply ran out, she was forced to prowl the city, hunting other creatures of Von Reichter's creation, such as Frankenstein's-monster-like "Fixed Ideas" or the more human-like "Technos", to murder them and take their Sustenance to survive. Almost by accident, she became a hero by defending the people of her city from Von Reichter's malevolent plans, often carried out by his cloned "son" José. Along the way, she meets the resurrected Data-7, as well as a young boy named Julian, and falls in love with biology teacher/reporter Lucas Amato, while her male alter-ego, Adrian, became the object of affection of one of "his" students.