The world is already collapsing by the time you meet the team. Gallactor doesn't monologue or wait for the heroes to assemble; it moves while the ISA is still burning. You're watching five people scramble to stay ahead of an enemy that is already winning, and the OVA never lets the pacing slip long enough for you to catch your breath. This is espionage thriller dressed as superhero action. By episode three, you understand why Nanbu had to choose these five specifically, not because the show told you, but because you watched them barely survive what came before.

In 2066, the Republic of Hontworl, a founding member of the United Nations, walks out of the organization without giving a reason, and the world is left on edge. Soon afterward, a flying, bird-shaped fortress called the Turtle King strikes Myori, capital of the Republic of Triad, while leading scientists of the International Science Organization start disappearing. Dr. Kouzaburou Nanbu, head of the ISO, sees the hand of the secret terrorist group Gallactor behind it and summons the five members of the Science Ninja Team, Gatchaman. Years after their last battle with Berg Katze and Gallactor, Ken, known as the Eagle, must lead the team once more in this three-episode action sci-fi OVA.