A kid inherits his dead father's super robot and finds out the entire city he grew up in was his father's blueprint for survival. The robot itself isn't the inheritance, the responsibility is. Daigo has to choose between the life his sister kept running and the life his father designed him to live, and the Gordian forces that choice every single episode. This is mecha that understands that the real weight isn't in the cockpit. It's in knowing someone else's dream is now yours to either complete or burn down.
After a cataclysmic event transforms the world into barren wasteland, humanity scrambles to rebuild from the ashes. Daigo Otaki grows up as an orphan, unaware of his family's true legacy until his sister Saori reveals the shocking truth: their deceased father designed Victor City, humanity's greatest refuge. More importantly, he left behind Gordian, an experimental super robot built to protect the city from threats. Daigo inherits both the machine and the burden of his father's unfinished work. He enrolls in the Mechacon 18th Regiment, an elite enforcement unit dedicated to defending Victor City against relentless attacks from the Madokuta organization. As he pilots Gordian in increasingly brutal combat, Daigo must grapple with questions about his father's real intentions, why the Madokuta won't stop coming, and whether the city his father built is truly the safe haven it claims to be. What begins as a straightforward mecha action story evolves into something more complex, blending mechanical warfare with personal discovery and political intrigue across a dying world struggling toward tomorrow.