Air date: 1998-09-05

Gamu Takayama is a 20 year old member of an organization called Alchemy Stars. After a monster known as C.O.V. attacked the Earth, Gamu falls through a portal of light and meets the giant: Ultraman Gaia, who gives him his powers. Later, when Gaia was in trouble in episode three, another Ultraman, Ultraman Agul appeared. Can they save the Earth? Who is Agul, is he friend or foe? Later in the series it is seen that Agul, too, is a being of justice, but only protects the Earth, not humanity. The conflict between the two later leads to a duel, opening a wormhole that allows a giant beast to reach Earth. What will happen then?