Jack was left on Kiiro no Kusa as a baby and taken in by the orphanage there. Growing up, he would often watch the lions that ruled the nearby savanna and eventually attempted to join them by challenging the pride leader. He was beaten easily, but the lions allowed him to become part of the pride when he proved himself by fighting and winning against one of the cubs. As time went on he would run with the lions at night and rest at the orphanage during the day.