Ultraman Gaia: Once Again Gaia is a 2001 tokusatsu Direct to Video film produced by Tsuburaya, part of the Ultra Series and a sequel to Ultraman Gaia.
A year after the defeat of Zogu, Gamu Takayama and Hiroshi Fujimiya began to live normal lives, Gamu as a student furthering his studies, Hiroshi living as a semi-recluse on his own. However, another threat will soon arise in the form of a surviving monster from Zogu’s army, Gakuzom. After a year of separation, the two heroes will once again join forces to save the world once again...
Tropes related to new characters in this spinoff is already on the series' main character pages.
Ultraman Gaia: Once Again Gaia provides the following tropes.
- Awesome Underwater World: The underwater population of seahorse-like Rinars, their civilization which was wiped out by Gakuzom prior to the series.
- Big Bad: Gakuzom, which is also a prophesied bringer of destruction.
- The Cavalry: The XIG pilots reinforcing Ultraman Gaia and Agul in the climax, when both Ultras are near the losing side of a Curb-Stomp Battle, allowing the Ultras to turn the tide around.
- Contrasting Sequel Antagonist: Compared to the Big Bad of the previous two Gaidens, which are human (or humanoid) and capable of some form of communication, Gakuzom is a monstrous brute who never directly communicates, with his actions conveying its personality.
- Dragon Ascendant: Gakuzom is one of the Roots of Destruction, like Zogu, and thus was one of the Radical Destruction Bringer's Co-Dragons. However, his master gave up, making Gakuzom now an independent threat.
- Flying Seafood Special: The Baiakuhe army, which resembles flying fishes the size of airplanes.
- Henshin Hero: Gamu and Hiroshi is back!
- Heroic Second Wind: With the crew of Team Marlin, sans Gamu, knocked unconscious and out of comission, the Rinars immediately enters the crashed submarine and donates their light into Gamu's Esplender, allowing him to transform into Ultraman Gaia once again.
- The Rinars shows up once again in the climax, when Ultraman Gaia and Agul have lost to Gakuzom, where they materialize en-masse into light particles into the Ultras' Colour Timers, recharging them to full strength for another rematch.
- Kaiju
- Late for School: Happens to Gamu (now a university student) early in the episode. While an excited schoolgirl asks for Gamu to pose Ultraman-style for her camera, a couple of Gamu's friends interrupts by reminding him classes is about to start.
- Make My Monster Grow: Gakuzom, upon realizing the combined might of Ultraman Gaia and Agul would be too much for him to handle, decide to absorb hordes and hordes of his Baiakuhe into his body, greatly increasing Gakuzom's size and powers and morphing the monster into a near One-Winged Angel form.
- Meaningful Name: The Baiakuhe are named after the Byakhee
from HP Lovecraft's stories. - Mystical Waif: Melissa, the mysterious, blonde-haired little girl that Hiroshi keeps seeing throughout his visions. Turns out she was the human incarnation of the underwater plankton-like lifeforms called Rinars.
- The Remnant: Gakuzom is a surviving member of Zogu's legion of monsters. Naturally, with Zogu gone, this new monster is eager to continue what its master have started.
- Say My Name: "GAMU!!!!!"/"FUJIMIYA!!!!" ( said by the respective heroes' love interests near the end of the climax, when they - in Ultra form - are on the losing side of the final battle against Gakuzom)
- Scare Chord: Used in the scene where Hiroshi meets Melissa the first time. The unexpected, high-pitch shriek out of nowhere can easily cause a Jump Scare for first-time viewers.
- What Happened to the Mouse?: Gamu, now a university student, has made several friends in classes, all of them which are aware of his identity as an ex-Ultraman. However, after the first 10 minutes none of them showed up for the rest of the episode, not even at the end when Gamu transforms into Ultraman Gaia once again, where the film shows crowds of civilians and citizens cheering for the Ultras. They do have a quick cameo in the credits though.
- Zerg Rush: Gakuzom's monster army of Baiakuhes, which attacks in large numbers even capable of taking down Ultraman Agul.
