At thirteen and in critical condition, Mariko was saved by TEQ63 after her tribe was obliterated by the Machines.
Safely in the care of another town, she received cyber prosthetics to survive. Enflamed by war she vowed to serve TEQ63 when fully grown, out of gratefulness, admiration, and the chance to enact vengeance for her slaughtered loved ones. She would spend her adolescence training for her chance, becoming an accomplished swordsman and gun specialist.
Upon adulthood, and already the most deadly warrior of her tribe, she would upgrade her cybernetic parts even further. This new level of lethality would prove to be a potent match for the machines.
In the heat of war, Mariko would discover TEQ63 on the battlefield, just as she remembered him. As fate would have it, she would even end up saving him during battle, and be recruited into the Bulletpunk Death Squad. It was only then that she revealed her identity to her new brothers in arms.
After all she had been through, Mariko developed feelings for TEQ63, but he is reluctant to reciprocate them.
On the battlefield she is a graceful and deadly warrior, often accompanied by a little Mecha Kitty named Necco at her side.