I was thinking it might help if we broke the history down on a timeline, and the Gunhand can place/move his live events around on it as needed:
YE 16: Raphael is born. The Third Elysian War begins. Somewhere during the war, Raphael's family moves to Planet Nepleslia to escape of fighting on Planet Yamatai. At some point his dad joined the military for the Empire, which at the time was called the Army of Uesureya.
YE 18: most Elysian territory was in such ruined condition that the populace made an exodus to
New Elysia and started the Elysian Celestial Empire
YE 21: The Star Army of Yamatai is formed.
YE 23: Fourth Elysian War starts (Elysian Celestial Empire vs. Yamatai Star Empire, which included Nepleslia). Raph is 7. Sometime during this war his father is killed.
YE 25: Fourth Elysian War Ends. Raph is 9.
YE 26: First Mishhu War starts
YE 28: Nepleslia achieves independence from Yamatai. The Star Army of Nepleslia is formed.
YE 29: Nepleslia is at war with the Reds for control of the Nepleslian Empire - Raphael is 13 - Second Mishhu War ends
YE 30: The Nepelslian Star Empire becomes the Democratic Imperium of Nepleslia. The SAoN becomes the NSMC (Marines) and the NSN (Navy).
YE 31: The Second Mishhuvurthyar War starts - Raph is 15
YE 34: 2nd Mishhu War ends - Raph is 18 - His mom disappears around this time. Raph joins the Marines.
YE 37: Present day. After a 3 year stint in the NSMC, Raph becomes independent.
My: suggestions: Have his dad join the military in YE 21 or 22 to be part of the Star Army, and then unexpectedly dragged into the war against his own people in YE 23.