Yūkimaru's Mother

Three-Tails Arrival arc
Some time during her son Yūkimaru's childhood, his and his mother's village was attacked by Orochimaru. Guren was one of the ninjas raiding the village, killing everyone she came over. When she collapsed, it was Yūkimaru's mother who tended her. When Guren woke up, she said she would close her eyes and let her escape as an act of gratefulness towards the kind woman. However, closing her eyes once didn't mean she could keep away from Orochimaru's orders, and when they met again out in the snow, Guren had to kill her to keep her master's approval.