A world poisoned from space, survivors clinging to an ocean floor turned sanctuary, one warrior and one weapon standing between collapse and survival. The 90 minutes burns through its premise like a fuse, trading breathing room for relentless forward momentum. What you get is pure visual spectacle married to a genuinely original threat, the kind of world-building that makes you wish this had been a full series instead of a special that had to cut itself down to fit.

Earth lies ravaged by shinobi, a poison that arrived on an asteroid and plunged the world into despair. Survivors have fled to Kairiku, land that was once the bottom of the ocean, where they struggle to shield themselves from the poison's effects. But even here, the threat remains. One hope is left: countering the poison requires the Holy Weapon Giga Road and the legendary warrior Yagyuu. Ame, a princess whose nation has fallen, rises to save the world. Part action and part fantasy, this one-episode special brings giant robot combat to a setting scarred by disaster.