Gamu Takayama is a brilliant young genius performing experiments on altering and projecting human consciousness. During one experiment, his mind is drawn into strange world where he sees a giant battling a monster. Almost unconsciously, he finds himself uttering the words "Ultraman." Meanwhile, a wormhole in space unleashes a wave of invaders at the Earth.

After struggling through his first battle as Gaia, Gamu is somewhat forcibly drafted into XIG. It soon becomes obvious that not all threats to the Earth will be arriving from outer space.

Wondering whether or not Ultraman is a defense provided by the Earth itself, Gamu christens his alter-ego "Gaia." Shortly afterwards a metallic organism heads to Japan and XIG moves to intercept.

A jellyfish-like monster with incredibly destructive powers seems to be immune to conventional attacks, and Gamu turns to his school friends to develop a weapon that XIG can then use to take the creature out.

Gamu still hasn't let his parents know that he's a part of XIG, and returns home for the first time in a while. Once home, a monster rises out of the water and the Ultraman who tackles it isn't who anyone is expecting.

When Gamu is baffled at how the monstrous Gan Q seems to defy the laws of physics, his faulty instructions cause the XIG offensive to go disastrously, and he sets out to find redemption along with an effective attack method.

A mysterious typhoon seems to be caused by something other than the weather, and it's up to XIG to prevent the unnatural disaster from wreaking too much havoc.

A mysterious entity is discovered at a dam, and XIG is given an ominous warning not to seek it out.

An unidentified object is emitting an intense heat that threatens to ignite a gas pipeline below.

XIG's all-women fighter group, Team Crow, gets a chance to prove to their commanders what they're capable of when a new threat emerges from the wormhole.

The investigation into a water shortage in Tokyo leads to the appearance of multiple dragon-like heads from underground, and Gamu has to guide Team Hercules to the location of creature's body.

A strange beast that appears to resemble a werewolf is the target as Team Lizard takes to the field. As Gamu attempts to discover the nature of the strange beast, he is confronted by Hiroya and their different philosophies collide.

The KCB broadcast team gets a tip about a town that's encountering strange phenomenon, but they get more than they planned for when its inhabitants attack them.

A wormhole near Jupiter sends Anti-Matter towards Earth. The potential reaction between it and normal matter could mean total annihilation. The Alchemy Stars work on a way to avoid this threat, but in the end it might take Gamu and Hiroya overcoming their differences to protect the planet.

The KCB broadcast team and GUARD come into conflict as the reporters attempt to investigate a strange green rain, and the monsters behind it.

His first meeting with Agul comes back to haunt Hiroya, and the origins in his opposing perspective to Gamu's becomes clear.

Fujimiya awakens a monster, Zonnel, with the intention of stopping an asteroid headed towards the Earth. While Fujimiya might want to preserve the planet, Gamu fears that he's not as concerned about saving human lives.

Hiroya's frustrations with humanity reach an apex as he enacts a plan to end what he sees as their futile hopes by destroying the Aerial Base. Gamu is the only one who can stop him.

Psycho Mezard targets Atsuko, who is locked in a delusion where the only way out might be to overcome her past.

Hiroya recovers a parasitic entity that has survived inside a fossilized dinosaur egg, bringing him once again into conflict with Gamu, who questions whether or not Hiroya's lack of concern for humanity is simply taking the easy way out.

A new threat that condenses oxygen appears under the sea. As XIG's Team Marlin heads underneath the waves to deal with the threat, Hiroya confronts Gamu with the knowledge that this monster is a product of industrial waste dumped by humans.

Staff Officer Chiba spends some time with his nephew, who seems to have lost hope for the future thanks to the constant threats lately. When a new monster appears from a wormhole Chiba, GUARD, and Gaia will have to fight to prove that hope for a bright future is still alive.

When his encounters with Hiroya are brought to light, Gamu's refusal to reveal secrets regarding the other Ultraman cause him to be censured by XIG.

Hiroya steals data on monster locations throughout the world and then uses Agul's power to rouse them, leading to a desperate battle between Gaia and Zonnel.

Gamu and Hiroya do battle as Gaia and Agul, but could their ideological clash result in even more danger for the Earth?

The consequences of Gaia and Agul's battle, and the nature of a new threat, shocks Fujimiya to his core.

As Gamu realizes that he can no longer rely on Agul's help in battle, Crisis releases a last ditch attempt to eliminate the forces defending the humanity.

A mysterious heat wave is threatening Gamu's hometown, and the cause might be something only Gaia can stop.

A member of Team Hercules, Satoru Yoshida, has a friend who believes himself to be an alien. However, is it fact or fantasy?

Atsuko's sister, Ritsuko, is in danger when the monster Gokigumon comes to town.

When a young boy develops psychic powers, Gamu needs his help in dealing with the threat posed by Gan Q.

Team Falcon seems set on sacrificing themselves to prevent a disastrous future they once shared a vision of, but Gamu tries to convince them that there's always another way.

Gamu visits Canada where he gets caught up in a situation between an invisible monster and one of the Alchemy Stars.

Team Hercules' Takanobu Kuwabara has a cousin who dreams of becoming a professional wrestler, a dream that might end up coming true when he receives a strange performance boost from a piece of a UFO.

A series of misunderstandings spins out of control when a GUARD transport plane crashes and the egg of an ancient monster falls into the wrong hands.

Hiroya returns to settle unfinished business, but does he still think wiping out humanity is the best way to save the Earth?

Hiroya is tempted by forces that want him to continue his efforts to destroy all humans.

Gamu is forced to consider the balance between humans and their environment again as a plan is enacted to preemptively destroy a monster that's currently deep in hibernation. Hiroya is faced with the consequences of his prior actions.

An old experiment by the government to turn people into deadly bio-weapons comes back to cause trouble for Gamu.

A group of children visit the Aerial Base for a tour, and get caught up in an attack by the monster Pazgeek.

Hiroya is despondent at what his actions have caused, but when Gamu is captured, Agul may be the only one who can save him.

Gamu is forced to face himself in more ways than one when news of the Destruction Bringer's location is on the verge of being discovered.

Experiments to clone extinct species attracts the attention of the Destruction Bringer, forcing Hiroya and Gamu to come face to face with a mutated version of a creature that humanity was responsible for the annihilation of.

When the home planet of the Destruction Bringer is revealed, a plan is enacted to launch missiles at it via a wormhole. Hiroya suspects humanity's aggressive response is exactly what their enemy is after, and convinces Gamu to try and shut down the attack.

The conflict escalates after humanity's failed assault on the Destruction Bringer, with Gaia and Agul both on the ropes against the unrelenting Blitz Blots.

When an old friend comes to believe that the destruction befalling Earth is a natural outcome, Gamu starts to wonder if humanity has beckoned these disasters.

Hiroya and Reiko find themselves aboard a gigantic entity that is on a collision course with Earth.

Despite the loss of the Aerial Base, the surviving XIG officers gather what they can and set out to back Gaia up in his battle against Zebub.

Gaia, Agul, XIG, and GUARD work together to fight off a massive invasion of insects.

Gaia and Agul face the immensely powerful angelic Zogul, with the eyes of the world upon them.

The Alchemy Stars and XIG enact a plan to restore Gaia and Agul's powers, as the monsters of Earth hold off the march of destruction unleashed by Zogul.