Dom Bombardi originally lived with his parents, who were both renowned mobile suit engineers, in Arizona, United States under the name Dominic Johnson. Dominic would become tired of all the suffering and war in the world and ran away from his priviledged, pledging he would find a way to help the world.
Though he met initial success, joining the military and becoming a mobile suit pilot under the Union, he was forced to run away again when his parents found him and threatened to take him away. Dominic stole an aircraft and attempted to escape over seas. He was eventually shot down after refusing to surrender over Africa, where his plane crash landed into a forest near the sea.
It was shortly after this that he became a member of Star Strike. He was found by Strafe who had gone out to scout the area for any possible threat to security. Strafe discovered a wounded and barely concious Dominic, who explained how he got there before collapsing. Strafe took pity on him and brought him to the base, where he recieved medical attention.
Grateful for the help he had recieved, and sympathetic to Celestial Being's cause, Dominic joined under the code name Dom Bombardi. During this time Dom would form a good relationship with Star Strike chief engineers Roy and Bill, the latter of which he formed a continous rivalry over who was better at rock paper scissors.
A year later he met Ransac Strike, who had just escaped the Super Human Institute and was rescued and brought to the base by Strafe Lenardo and Longshot. Despite initial hostility between Ransac and the members of the team, Dom would become Ransac's best friend during his first year as part of Celestial Being.
Dom was one of those surprised when Ransac became the pilot of the Rush Gundam instead of Strafe.
Dom was a highly optimistic person. He always sought to look at the better side of things instead of focusing on the negative, a trait that sometimes put him at odds with the pessimistic Longshot. He was also highly curious, always wanting to learn new things when it interested him, though this sometimes got him into trouble. Because of his young age and privilaged lifestyle, Dom developed a very outspoken and mischievious personality, not being afraid to tell things how he sees it and almost always pulling off a joke within his team. This caused him to come across as naive at times. He highly enjoyed a good joke, making it his personal mission to bring some humor into the group. Dom was also stubborn, refusing to take no for an answer when he had his eye on something, primarily when it came to Syrene Gaze, who Dom had developed a crush on shortly after joining the team.