Under Char Aznable's command, he and his colleagues, Crown, J.Q., and others, challenge the SCV-70 White Base just before it enters the Earth's atmosphere. When they were unable to approach the White Base due to its heavy fire, Char gave them a stern rebuke, telling them to approach and strike. Later, when in combat with the Gundam, Kohm loses his Zaku machine gun to a direct hit from the Gundam's Hyper Bazooka. He then holds a Heat Hawk in his left hand and tries to launch a pincer attack with Char's Zaku against the Gundam. However, the Gundam Hammer wielded by Amuro's Gundam struck his Zaku in the left armpit, and he was killed in battle.
In the manga "Mobile Suit Gundam: The Origin," he appears under the name Joseph. He was the only one of the three to survive the atmospheric entry battle, along with Char, but was later destroyed from behind by the Gundam in the ground battle.