The King of Braves GaoGaiGar

It takes place in 2005 (initially referred to only as "the 21st Century"), two years following an incident where the first identified extraterrestrial intelligence—classified as "EI-01"—crash-landed on Earth and absorbed a large number of machines into itself before disappearing without a trace. Following this incident, the Japanese government created a secret organization to combat potential alien threats: the Gutsy Geoid Guard, or "GGG", based beneath G-Island City in Tokyo Bay. Parasitic alien life-forms known as "Zonderians" have begun to emerge; using the Zonder Metal of which they are made, they can assimilate various kinds of matter to form "Zonders." which use humanoid beings as their hosts.

GGG gains three key resources with which to combat this threat. There is Galeon, a sentient mechanical lion of alien design. There is the alien child Mamoru Amami, whom Galeon had left with human parents eight years earlier. The third asset is human cyborg Guy Shishiō, whose life was saved by Galeon two years earlier and is capable of fusing with him, forming the mechanoid GaiGar. When combined with the GGG-made GaoMachines, GaiGar becomes the Super Mechanoid GaoGaiGar: a mecha capable of defeating Zonders, recovering their cores for Mamoru to "purify" and saving the human host in doing so.

GaoGaiGar is composed of 49 episodes, first aired on Nagoya TV from February 1, 1997 to January 31, 1998. It was followed by a number of works across multiple media (one serialized novel, two short stories, one PlayStation video game, at least two serialized manga and four audio dramas). Most of these works contained plot written by Studio 7 staff, and contributed to its canon long after its airing.

The show's popularity would soon warrant a new animated work. This resulted in the production of the eight–part sequel OVA The King of Braves GaoGaiGar Final, released from January 21, 2000 to March 21, 2003. Its story takes place one year following the events of the television series, and incorporates characters and continuity from non-television works. Examples include Renais Kerdif-Shishioh (main character of the aforementioned novel) and Rose Approval (secretary general of the United Nations as seen in the aforementioned PlayStation game).

In its production, Studio 7 further ensured that there were no actual betrayals in the show; any "betrayal" automatically resolves itself as a secret that had to be kept to the main characters' benefit. This was perhaps partly due to the fact that GaoGaiGar was made as a children's show, and partly as a commentary on the heavy air of distrust and conspiracy occurring in mecha anime.

In the first half of the television series, other, minor themes are introduced, nearly all of them ultimately discarded in favor of the main themes of courage and bravery. The first episode begins on a place called Garbage Island ("gomi no shima", an analogue to Japan's own "Dream Island" or yume no shima found in Tokyo Bay) and speaks about ecology and the environment. Outside of that one episode, this theme is only followed up on briefly, in one other moment of the entire series. Another discarded theme is that of self-betterment: in the first half of the series, the Zonderians mostly make Zonder Robos of stressed-out, discontent "average joe" types—a truck driver who hates traffic, for instance, or a morbidly obese man tired of being picked on. Once Mamoru purifies them, however, their attitudes toward life become less obsessed (and in the case of the obese man, the source of stress is removed), the stress having been exhausted from their system when in Zonder form.

It is also notable that GaoGaiGar's narrator and its next episode sequences—and the episode titles themselves, in some cases—rely on extreme hyperbole, even lying to the viewer if deemed necessary. This in itself is a Super Robot trend, dating back to Mazinger Z, the original Super Robot show (which itself used hyperbolic episode titles such as "Kouji Kabuto Dies in Lava").

• Guy's transformation sequence may have been inspired by many famous Henshin (transforming) heroes like Kamen Rider and Science Ninja Team Gatchaman.
• GaoGaiGar's Broken Magnum and Broken Phantom attacks have the behavior of a "Rocket Punch", where the robot's arm up to the elbow is fired at the enemy in similar fashion to that of a missile. This sort of attack is a staple of many early Super Robot shows, dating back to the first one of its kind, Mazinger Z, where the name "Rocket Punch" originated.
• GaoGaiGar's Protect Shade and Protect Wall defenses are reminiscent of similar moves (albeit usually two-handed) by Ultraman and other Ultras.
• The title of the very first episode of the series ("Yuusha-Oh Tanjou!", or "The King of Braves is Born!") may possibly be a reference to the title of the first episode of Mazinger Z ("Kyoui no Robot Tanjou", or "Birth of the Robot of Wonder").
• A few themes of GaoGaiGar tie into the popular manga artist Masami Kurumada. The names of GaoGaiGar's Broken Magnum and Broken Phantom attacks are references to the "Galactica Magnum" and "Galactica Phantom" attacks used Kurumada's boxing manga Ring ni Kakero. Likewise, Cyborg Guy's Ultimate Armour and the ID Suits visually resemble Cloths from Saint Seiya, another Kurumada work.
• The character Ayame's PHS (cellular phone) has a shape similar to that of the Ultra Eye transformation item used in the Ultraman series Ultra Seven. When opening it, Ayame makes a similar pose as Dan Maboroshi did when using the Ultra Eye. (Some materials even refer to the phone as the "Ayame Eye.") As it is referred to as "Ayame's PHS" in the pre-commercial cut, it may be a custom design.
• Soldat J's character (hair, elongated nose, love of the sky) is partially based on that of Jet Link (Cyborg 002) from the manga Cyborg 009 (he is even referred to in an Episode 40 flashback as "number J-002"). Similar to Jet, J displays the ability to accelerate beyond what the eye can see, however briefly. The two characters also share the same ideas about the sky and flight. Soldato is Italian for soldier.
• Hana Matsuno reveals Mamoru's identity as an alien to their friends in the last episode in an almost identical manner as Annu revealing Dan Maboroshi's in the last episode of Ultra Seven.
• Cyborg Guy's Hyper Mode sequence bears some resemblance to Juushin Liger's transformation (specifically, his swinging his hair around).

• Transformers: Galaxy Force (Transformers: Cybertron in the US) contains many visual references to GaoGaiGar's stock "Final Fusion" and "Hammer Connect" sequences, most notably in the sequences where Liger Jack (Leo Breaker) and Sonic Bomber (Wing Saber) "Link Up" with Galaxy Convoy (Optimus Prime). Galaxy Convoy's chest and shoulders also bear physical resemblance to ChoRyuJin, as does Omega Supreme from Transformers: Super Link (Transformers: Energon in the US). In the US series Transformers Animated, Safeguard's combination sequence is in homage to the sequence of RyuJin combinations.
• The stock "Final Fusion" sequence is extremely iconic of the show, making it worthy of a great many fan parodies (though reaction to these parodies by other fans is greatly mixed). One recent fan-parody video (by the group MAD) intersperses soundtrack and footage of the Impulse Gundam combination sequence from Mobile Suit Gundam SEED Destiny with that of GaoFighGar's Final Fusion sequence from GaoGaiGar FINAL. Most of these videos ironically do not use GaoGaiGar's sequence audio, but rather GaoFighGar's from Episode 4 of FINAL, as it is the only version where the sound effects synced with exactly one rendition of the music track.
• In Yu-Gi-Oh! GX, the character Sho Marufuji (Syrus Truesdale in the English version) plays a Fusion monster "Super Vehicroid Stealth Union", a monster that is a fusion of a drill rig, a bullet train, a stealth fighter and a semi truck, and is a clear tribute to GaoGaiGar. And in addition, a Duel Monster spirit Kaibaman bears resemblance and homage to Soldato J.
• The character Subaru Nakajima from the Magical Girl Lyrical Nanoha StrikerS anime possesses a number of nods to GaoGaiGar, some of them incredibly blatant. Her transformation sequence in the show includes at least two direct visual references to GaoGaiGar in that she is surrounded by a tornado of green fog prior to transformation and that a jewel slides into place on her device Mach Caliber in exactly the same manner, and with exactly the same dimensions, as the crown G-Stone in GaoGaiGar's Final Fusion. If the video is switched around in some locations, the sequence matches the sound effects as well. (Original Final Fusion video here, brief clip of the henshin in question (with Final Fusion music mixed into the background as comparison) here. Warning, second link may not be work safe.) The character has exhibited at least two abilities that are strikingly similar to GaoGaiGar's Broken Magnum and Protect Shade respectively. Certain members of the fan community, namely the Otakuism blog, thus refer to Subaru as "GaoGaiGar-tan".
• Given the timing of the show's release and design of the "nose" and paintjob of LinerGao, it seems extremely likely that LinerGao is meant to specifically be a modified 500 Series Shinkansen, which was put into regular service roughly a month after the first episode of GaoGaiGar aired.
• The series also appear in Harobots, from being one of Sunrise's series. This series' units can act as 'wild' units or as the player's units.
• A parody of GaoGaiGar is featured in Hayate no Gotoku. A character named Cyborg Butler appears in the 38th episode, has the same hairstyle like Guy (though fans noted that his face looked more like Viral of Tengen Toppa Gurren Lagann) as well as his voice actor Nobuyuki Hiyama (also voices Viral and Guy). He is also prone to yell dramatically or shout Gagagagagaga while running. His attacks are all parodies of Drill Knee, Broken Magnum, Hell And Heaven and Goldion Hammer (he even shouts Hikari ni Nare!!! like Guy while doing it). Before he uses the Goldion Hammer parody, his superior tells him that the move is approved (just like Taiga approving Goldion Hammer for use). In his last moments, he also makes a statement regarding of courage. The link between Guy's and Viral's visual styles as well as the over-the-top yelling and attacks that the voice actors are known for might indicate that it was more of a parody of Nobuyuki Hiyama himself rather than any one of his portrayed characters.
• In Super Robot Wars Original Generation Gaiden, Kai Kitamura's Gespenst Mk II M Custom's signature move is the Jet Phantom, an upgrade from the Jet Magnum.
• In Kimi ga Aruji de Shitsuji ga Ore de, in the episode 8, the character Kojūrō Takeda (voiced by Guy's voice actor, Nobuyuki Hiyama) beats up the main character Ren Uesugi (voiced by Tomokazu Seki from Mobile Fighter G Gundam), in the same vein of Guy beating up Palparepa in GaoGaiGar Final, all while preaching the virtue of love towards one's master (instead of courage). He later charges towards Ren by yelling "HIKARI NI NARE!!!" after Ren shouts Bakunetsu God Finger!!!.
• In the summer of 2011, SanThree (Sanyo Bussan) introduced a pachinko machine, Brave King GaoGaiGar CR, based upon the series.
• In Super Robot Wars Z, a mech called Gunleon can be considered a homage to GaoGaiGar. Gunleon is a lion-themed robot, that uses construction tools as weapons and is powered by a glowing green energy source. Two of Gunleon attacks involve it transforming into Magna Mode which heavily resembles Genesic GaoGaiGar.
• In the last episode of Yahari Ore no Seishun Love Come wa Machigatteiru, Zaimokuza (voiced by Nobuyuki Hiyama who voices Guy in GaoGaiGar) does a "Zaimokuza Crusher" shouting it out in a similar way to the "Goldion Crusher".
• In episode 19 of Gundam Build Fighters Try titled "Fateful Reunion", there is a Psyco Gundam MK-II colored after King J-Der that was coincidentally defeated by the Gundam Tryon 3, which, while based on the super robot genre, has a lion mecha forming the chest/body very similar to Galeon/GaiGar for GaoGaiGar.
• In Bomberman Generation, the fourth boss is a large robot called Constructor X that is a combination of two AI-based construction vehicles that sports green and yellow colors and addressed as brother units similar to GekiRyuJin.

• The King of Braves GaoGaiGar Final
• Betterman

• Official GaoGaiGar Website (Japanese)
• GaoGaiGar: King of Braves (anime) at Anime News Network's encyclopedia
• The King of Braves GaoGaiGar (NBN)
• Brave King GaoGaiGar pachinko game (in Japanese)