Scuba instructor Daisaku Kusama discovers an ancient ruin beneath the sea. When the experience lures him back, he unwittingly awakens an ancient titan - and a power that now belongs to him.

Daisaku is taken into custody by UNISOM while they scramble to keep GR-1's awakening under wraps. When the terror organization GRO deploys one of their own robots to destroy GR-1, Daisaku must put his newfound power to the test.

GR-1 fends off GR-2 in Daisaku's first battle. McKenzie takes Daisaku home to tie up loose ends with his estranged mother, but the reunion is short-lived when danger strikes.

GRO ambushes and captures GR-1 while separated from Daisaku. Stranded in Tokyo, the reluctant GR operator must now figure out how to free his robot from so far away.

UNISOM fakes Daisaku's death to protect him from GRO. The military organization's less-than-moral measures, combined with GR-1's collateral damage, give the young hero pause.

GR-1 and the airborne GR-3 clash in Odaiba, but the enemy GR's psychopathic operator is too much for Daisaku to handle. Unless he can determine his own reason for fighting, Daisaku's robotic partner will be captured for good.

BFN journalist Maria Vovnich follows a lead on the GRs while Daisaku is transported to Nevada for study. Hodges, unable to fail GRO leadership again, plans a counterattack.

At UNISOM's Nevada base, Daisaku is introduced to "Disaster:" a salvaged GR with a striking resemblance to GR-1. Daisaku is warned by V that the GRs shouldn't fight, but has no choice when GRO launches a full-frontal attack.

GR-2 returns for a rematch at the Nevada base, but proves to be a distraction for GRO to capture Daisaku. UNISOM's finest must protect their operator - at any cost.

GRO narrowly captures Daisaku, who learns Hodge's personal motives. To prevent GR-1 from falling under enemy control, UNISOM decides to transplant its Avatar into Disaster.

Vovnich & Chang go rogue to expose BFN. Daisaku is delivered to GRO's HQ, where he meets V's "mother." Hodges fulfills his final duty in protection of GRO.

Texas - operating the newly-repaired Disaster - settles his score with Hodges. Daisaku tries to escape the crumbling facility with V, but not before GRO's secret leader requests an audience.

The gods have judged mankind unworthy and resolve to wipe Earth clean with V as their Avatar. GR-1 & Daisaku will stop at nothing to save mankind, rescue V, and carve out a new future.