After breaking out of prison in a distant corner of the universe and destroying the Galaxy Police Headquarters, Kain, an outlaw of intergalactic proportions, sets his sights on a more significant target: planet Earth. Meanwhile, Tenchi Masaki and his crew are watching old home movies of his mother, Achika, when suddenly she starts to disappear. To their relief, Washuu Hakubi's invention saves Tenchi from the same fate. However, they soon discover that Kain's actions have triggered a chain of events that altered time and caused Achika's vanishing. To protect their future and rescue themselves, Tenchi and his companions travel back in time to thwart Kain's schemes and keep his mother safe.