Many years ago, the Sacred Galaxy Empire collapsed; chaos ensued, and today an epic struggle for control of the cosmos continues throughout outer space. Several kingdoms vie for power and battle it out in fleets of spaceships, and skirmish on the ground in ancient samurai castles. One such soldier is Rai Ryuga, a go-getter who finds himself quickly promoted from the execution chamber to the role of a commander and beyond. Against fierce generals, alongside newfound comrades and in the midst of betrayal, love and determination, Rai will become a major player in an all-out war that spans galaxies and empires alike.
In the distant future, mankind has mastered space and spread empires across the galaxy. While many choose to colonize distant planets, others choose to remain amidst the stars, ultimately giving rise to a new brand of humanity known as the Abh. Both genetically and culturally different from their Earth-dwelling peers, the Abh soon find themselves engaged in a bloody war that rages across hundreds of planets and set out to restore peace by means of conquest. Enter Jinto, a nobleman and ambassador of the recently acquired Hyde system whose duty is to represent his peoples' interests and rule on the Abh's behalf. In order to be officially coronated to this position, a cold-but-beautiful Abh princess named Lafiel arrives at Hyde to escort him back to the empire's capital. When they are suddenly attacked by an anti-Abh liberation front, however, the festivities are cut short, and the two must flee for their lives against all odds.
If large-scale political space battles is your thing, try out the Crest of the Stars quadrilogy. Keep in mind that the original (CotS) is more of a small-scale character study, but its sequel will remind you of Thunder Jet (just way, way better).
The war between the monarchical Galactic Empire and the democratic Free Planets Alliance has raged ceaselessly across the galaxy for over a century, with the fleets of both powers having fought countless battles. Currently the conflict revolves around the strategic Iserlohn Corridor, one of only two passages of space through which the two forces can access each other. Here the Empire has built the nigh-impregnable Iserlohn Fortress, whose deadly weaponry has thwarted repeated efforts by the Alliance to capture her. Phezzan, a neutral mercantile state, controls the other corridor. The long war has resulted in an indecisive stalemate, but there are two men from the two worlds who will change everything: Yang Wenli, a gifted strategist from the Alliance who wants nothing more than to retire and be a historian; and Reinhard von Lohengramm, a man from the Empire whose ambition knows no bounds. Their loves, struggles, triumphs and failures play across an interstellar stage of intrigue, war and death.
Thunder Jet is a blatant ripoff of LotGH in almost every single way - that is, except the bishounen men have been replaced by ugly, Slayers-like character designs and random, confusing elements such as samurai are thrown in for good measure.
I have no idea why, but if you managed to like Thunder Jet, give what it's copied from a try.