It is revealed that several years ago when she was still with Masters in America, their team was fighting a number of low class foes from AU. At one point, she was told to split away from the rest of them. After she did so, they were attacked by a class A threat. They were decimated due their low Hybrid Count from the previous fighting. When Yurishia was informed about the situation, she ignored the order to abandon her comrades and managed to save all of them. However, her comrades believed that she tricked them in order to appear as the hero and began to distrust her. She eventually left for Ataraxia and when she encountered the Masters later, Kizuna helped repair their relationship by revealing the truth of what happened.