Judau lived in the space colony of Shangri-La in Side 1 with his little sister Leina Ashta. Judau and Leina's parents moved away from the colony to find work and send money back to them, leaving Judau to care for his younger sister. To make enough money to put Leina through private school, Judau worked as a junk trader in the Shangri-La junkyard.
One day, Judau and his friends came across an escape capsule containing Yazan Gable, a surviving Titans soldier from the Gryps conflict. Yazan forcefully recruited Judau and his friends to steal the Zeta Gundam from the Anti-Earth Union Group, but during the attempted heist Judau and his friends betray Yazan and attempt to steal the Gundam to sell it. After multiple attempts to steal the Zeta Gundam, which usually ended in Judau inadvertently saving the AEUG from the Neo Zeon forces, Judau befriended multiple members of AEUG and decided to join them in their fight against Neo Zeon, becoming one of the pilots in their Gundam Team. He later received the MSZ-010 ZZ Gundam from Anaheim Electronics to pilot in battle against the Neo Zeon forces, becoming wingmates with Roux Louka.
The Neo Zeon forces later kidnap Leina, causing Judau to make multiple attempts to rescue her. During one of these attempts, Judau infiltrated the Axis Colony and encountered the Neo Zeon pilot Elpeo Ple, who eventually defected to the AEUG due to her crush on him. He also encountered Neo Zeon's leader, Haman Karn, who became intrigued by his good nature and idealism. Falling in love with Judau, Haman would make multiple attempts to convince him to defect to Neo Zeon's side in their various encounters across the Neo Zeon War. The two would have discussions about each other's philosophies, though they always ended with Judau rejecting Haman and her offer to join her.
During the skirmish at Dakar, Judau encounters Haman again. Haman shoots at him, but Judau's sister Leina leaps in front of him to block the bullet, causing her shoulder to be grazed. Judau's rage over his sister being injured awakens his powerful Newtype abilities, frightening Haman and causing her to run away in tears. While escaping with Leina, later in the battle Leina was seemingly crushed by a falling mobile suit, though Judau sensed her presence and that she was still alive somewhere.
Judau later witnessed Neo Zeon's devastating Dublin colony drop. In the ensuing battle, Judau was attacked by Ple Two in the Psyco Gundam but Elpeo Ple sacrificed herself to defend Judau.
When Glemy Toto attempted his coup against Haman Karn, triggering a split in Neo Zeon's ranks, Judau and the rest of the AEUG exploited the civil war within Neo Zeon to make their move and launched a joint attack with the Earth Federation Forces on Axis. After Judau killed Neo Zeon's flying ace Rakan Dahkaran and Roux killed Glemy Toto (though in the manga Judau kills Glemy as well), Judau faced off against Haman in a one-on-one Mobile Suit battle. Judau defeats Haman, but spares her life. However, upon realizing that the Earth Federation and AEUG forces were surrounding them, Haman took her own life. Right before dying. Haman told Judau she was happy to have met "such a good kid".
After the war, Judau got together with Roux and the two quit the AEUG to join the Jupiter Energy Fleet, traveling to Jupiter to start a new life together.
Anti-Earth Union Group