Somewhere in Japan, a bright light suddenly blasted from the ground. The light in a blink destroyed everything within a radius spanning hundreds of miles. The spot where the light appeared was immediately closed and the government sent in a special investigative team.
People argued that falling space debris caused it; others felt that the unusual movement of terrestrial magnetism caused the light. The truth, however, remained hidden and blurred from people's memories.
What people didn't know was, the light signals the approach of the one who would terminate the human race.. the ringing of the bell to let everyone know that the war has begun. A signal emerges from the light, but no one notices except for a little girl.
Ten years later, an army of giant robots suddenly appears and devastates the Earth. They call themselves "EX Tartaro" and their mission is to "purify the world". Every nation's armed forces were destroyed, not even nuclear weapons or star wars satellites had an effect on the four major robots- the Four Kyokuoh. A white wall, a shield, appeared in front of the Ex Tartaro while it attacked the city at breakneck speed. Three battle robots, the Dangaioh, defeated the enemy using well honed battle strategies. Sensing the strength of their enemy, the Ex Tartao united to form one giant robot. The three members of the Dangaioh team united into Dangaioh to reveal their true powers and eventually destroyed the invading force.