Under the wicked advice of his mystical advisor Witch Honerva, the evil King Daibazaal sends a Deathblack Beastman monster to the planet of Altea to search for the missing Earthlings. But the team is ready to fight back as they search for the last key to the fifth robot lion of GoLion! Will they find the missing key before the Kingdom of Altea is wiped out once and for all?