Kaci was taken at birth from an unknown village to Otogakure by Orochimaru. Orochimaru experimented on him and taught him many forbidden jutsu. After Seireitou Hyuga staged a rebellion and took over Otogakure, Kaci left for the Land of Mountains. He was confronted by Viper Uchiha a year after he arrives and allows him to join Kagekenin. He then acts as the groups spy.