Space Pirate Captain Herlock: The Endless Odyssey (SPACE PIRATE CAPTAIN HERLOCK OUTSIDE LEGEND 〜The Endless Odyssey〜) is a science fiction OVA, functioning as a sequel to the original Captain Harlock anime. However, this series follows the loose continuity of the Leijiverse which puts the narrative nature into question.
After the battle with the Mazon, some members of Arcadia's crew went their separate ways such as Kei Yuki captaining her own pirate crew. However, Kei is captured by the Space Sheriff Security to capture Captain Harlock.
Meanwhile scientist Dr. Daiba and his son Tadashi are on a junk planet away from Earth for research on the frontiers of the outer regions. Dr. Daiba has been killed with Tadashi believing it to be caused of aliens called the Gnu. When he is about to be killed by a wild beast, Tadashi is saved by Captain Harlock. Inspired by what Harlock said to him about being his own man, Tadashi joins Harlock's crew.