After Priss was orphaned during the Second Great Kanto Earthquake she was forced into an orphanage where there was no room for warmth. The atmosphere was gloomy and dark; her childhood was taken from her in an instant. Priss rapidly built up a protective emotional shell so that she would not have to deal with her grief as most people did. Because of this, by the time she was a teenager Priss was incredibly angry and unwilling to submit to authorities. When she was seventeen she ran away from the orphanage and joined a biker gang to reclaim from of her lost freemdom.
Even when she had found love and was happier than before, Priss yearned for something more. She was still all but a child when her lover was assassinated by GENOM, forcing Priss to harden herself to pain and suffering even more. Convinced that revenge was the only thing way to right that wrong, Priss went after her boyfriend's murderers. She was stopped by Sylia Stingray and after a 'discussion' Sylia had Priss believe that she would take care of her if only Priss would focus her sorrow on a more effective channel. Thus, Priss was taken into the Knight Sabers.
She suffers from a poor temper but overall Priss is a kind, caring person who looks out for her friends and loved ones. She depends heavily upon support from the other Knight Sabers, most notably Sylia, to get her through her unhappiness. Priss is somewhat unstable and prefers to avoid being social with others but she does make friends and is the most loyal of the Knight Sabers; she would surely give her life for those who are dear to her if that was the only way to save those people.