Years before the Clone Wars, Simocadia was attacked by an enemy army. Jedi Knight Mace Windu challenged the invaders, but was captured. Yojan, along with three others, rescued Mace, and together they drove off the enemy. Grateful to the Jedi for his help, Yojan swore a bond of friendship with Mace before he departed.
Yojan's funeral proccession.
After the outbreak of the Clone Wars, Simocadia became a contested planet due to its rich agrocite resources. Eager to remove his home from the war, Yojan came up with a plan. Using an ancient mechanical construct called the Ardana Shadex, he attempted to destroy the agrocite mines, but was interrupted by Mace Windu, now a Jedi General. Yojan activated the device but was unable to control it. As it rampaged toward the Royal City, Yojan was able to infiltrate the machine and trigger a kill switch. Unfortunately, he became trapped inside and was subsequently killed.