Yojan was born to Empress Sephani and a Prince who belonged to the Simocadia royal family.
Simocadia faced an attack from a hostile army in the years leading up to the Clone Wars. Mace Windu, a Jedi Knight, stepped up to confront the invading forces, but ended up being captured. Yojan, in collaboration with three companions, successfully freed Mace, and together they repelled the enemy. Before Mace's departure, Yojan, expressing his gratitude for the Jedi's assistance, pledged a bond of friendship to him.
Following the beginning of the Clone Wars, Simocadia became a battleground because of its abundant agrocite reserves. Determined to shield his planet from the conflict, Yojan devised a strategy. He sought to obliterate the agrocite mines using the Ardana Shadex, an age-old mechanical creation, but his efforts were thwarted by Mace Windu, who was now a Jedi General. Yojan initiated the machine, only to find himself unable to govern it. As it spiraled out of control towards the Royal City, Yojan managed to enter the machine and activate a self-destruct mechanism. Sadly, he was caught within the device and met his demise.