Endless Waltz is both the sequel and the prequel for Gundam Wing.It is set after the events on A.C. 195,where Earth has finally achieved peace. World Nation leader Treize Khushrenada has been slain and White Fang leader Zechs Merquise has disappeared.

In a time of peace, Gundams were no longer needed, and Quatre proposed the idea of the destruction of the Gundams. All the pilots agree, except for Wufei, who has disappeared with his Mobile Suit after the battle against White Fang. When the Gundams are collected and sent to a one-way trip to the sun, a crisis breaks out! Relena Peacecraft, now deputy foreign minister of the Earth Sphere Unified Nation, is abducted during a diplomatic visit to the colony X-18999 at Lagrange point 3. Her captor is the sinister child Mariemaia Khushrenada, heir to the Barton Foundation's business empire and daughter of the late World Nation leader. Mariemaia plans to follow in her father's conquering footsteps, and hopes that the former Queen Relena will serve her as a propaganda tool.. Without the Gundams, the 4 Gundam boys face an extremely difficult situation.But unexpectedly, Wufei appeares to be one of the rivals, working for the Barton Foundation. Zechs returns as a Preventer agent codenamed "Wind", and winds up fighting along side the heroes.