A scientist watching his world die builds a giant robot out of desperation, not heroism. The empire doesn't monologue or hesitate, they are simply conquest, methodical and grinding, which makes every episode feel like Earth is actually losing. Mechander Robo itself is the last gamble of a dying planet, and the show treats it that way, refusing the comfort of knowing the heroes will win because the setup never promises they will.
Earth stands on the brink of annihilation. The Doron Empire, a militaristic force from Ganymede, has launched a devastating invasion across the planet. Their ruthless commander, General Ozmel, seized power back home and now turns his attention to conquering worlds beyond his own system. Humanity's defenses crumble under the onslaught, and nearly the whole planet falls under alien control. Dr. Shikishima refuses to surrender. He unveils his final gambit: Mechander Robo, a colossal war machine built specifically to counter the alien threat. He recruits three pilots to crew it: his own son Ryosuke, Kojiro Hachijima, and the enigmatic Jimmy Orion. While the battle against the Doron Empire rages on, something hidden in Jimmy's past turns out to be linked to the wider conflict. The fate of Earth rests in their hands.
