Gundam Wing: Endless Waltz is the sequel to Gundam Wing, which is set in an alternate universe to the original Gundam series.
Trieze Krushrenada died, and Oz came to and end. Time passes before Mariemaia Krushrenada, Trieze's daughter, proclaims herself emperor of the United Nation. She then puts a rebellion in place just to take sure that she gets the title. She also kidnaps Relena Peacecraft. As the Gundam pilots investigate further, they find out that Dekim Barton is the pupetteer behind Mariemaia. Dekim is the father of the "real" Trowa Barton that Triton Bloom, better known as the "fake" Trowa Barton, killed. The Gundam pilots have to stop Dekim before he ends up ruling the United Nation.