The project was unofficially announced by Nikkan Taishu on March 6, 2019, followed by an official announcement by Tsuburaya Productions on August 1, 2019, with the latter revealing Higuchi as the director and Anno as the screenwriter. Masami Nagasawa, Hidetoshi Nishijima and Takumi Saitoh were named to star in the film. The film would be co-produced between Toho Pictures and Cine Bazar and presented by Tsuburaya, Toho and Khara, with an aim for a 2021 release. Higuchi commented, "A baton has been entrusted to me that has been shining ever since I was a small child. I will solemnly strive to fulfill my responsibility to pass on that heavy, radiant baton created by my seniors." The rest of the supporting cast members were announced in September of that same year.
The art book, Shin Ultraman Design Works (シンウルトラマン デザインワークス, Shin Urutoraman Dezain Wākusu), became available to purchase at theaters in Japan on May 13, 2022, distributed by Khara studio, and was released to bookstores by Ground Works on June 24, 2022. Hideaki Anno authored the book, which contains over 500 artworks, including concept art, CG models, and 3D objects. In June 2022, Poplar Publishing released Shin Ultraman Millennials Book (シンウルトラマン .mw-parser-output .templateruby>rtfont-feature-settings:"ruby"1;font-size:85%.mw-parser-output .templateruby.largefont-size:250%.mw-parser-output .templateruby.large>rtfont-size:50%MILLENNIALS BOOKミレニアルズ ブック, Shin Urutoraman Mireniaruzu Bukku), a 32-page book celebrating the film's release and the 55th anniversary of the Ultraman franchise. On June 28, 2022, Kodansha released ULTRAMAN HISTORICA: From Ultra Q to Shin Ultraman (ULTRAMAN HISTORICA ウルトラQからシンウルトラマンまで, Urutoraman HISTORICA Urutora Kyū kara Shin Urutoraman), a mook detailing every entry in the Ultraman series for adult fans of the franchise.
Mefilas meets with Kaminaga in a park, attempting to persuade him to accept his pact with the humans. Kaminaga asks what Mefilas' true intentions are, and the alien reveals that he intends to use the Earth's human population as bioweapons through the Beta Box. He also admits that he orchestrated all of the prior Kaiju attacks as well as Zarab's recent invasion in order to ensure the success of his plan. The first few Kaiju were dormant bioweapons on Earth that he activated and passed off as consequences of human advancement, after which he began unleashing his own advanced bioweapons with Pagos, Neronga, and Gabora. This lured Ultraman to Earth, who in fusing with Kaminaga demonstrated that the Beta Box's technology was compatible with humans. He used Zarab to make humans fear the threat of extraterrestrials, and his own demonstration of the Beta Box to make humans feel intellectually inferior and powerless, all to ensure the success of his plan. When police surround both of them, Mefilas uses his powers to teleport himself and Kaminaga to a bar to continue their discussion in peace. Mefilas reminds Ultraman that by the laws that govern both of their people, Ultraman is forbidden from interfering with the humans' treaty with Mefilas. Kaminaga responds that while Ultraman may be forbidden to interfere, the human with whom he bonded is obligated to fight back. Mefilas expresses his disappointment that they could not come to an agreement, and leaves.
Kaminaga meets with the SSSP and apologizes for involving them in all of this, but asks for their help in stopping Mefilas' plan. He says that their only option is to recover the Beta Box before Mefilas hands it over to the Japanese government, but unfortunately it is currently stored in the Planck Brane dimension, making it impossible to find using sight. However, Kaminaga says that by tracking the smell of Asami, who was in contact with the Beta Box, he may be able to find it. At the formal ceremony where Mefilas is to hand over the Beta Box, Ultraman's hand suddenly extends through the Planck Brane and grabs it. Mefilas tells a government official that he will be back, then transforms into his true form and grows to gigantic size. Ultraman throws the Beta Box into a chopper piloted by the SSSP, and they take it away. Mefilas confronts Ultraman in a nearby refinery, and the two extraterrestrials trade blows. Ultraman tosses Ultra Slices at Mefilas, who easily deflects them. Ultraman fires his Spacium Beam, which collides in midair with an energy beam fired by Mefilas. Mefilas boasts that while Ultraman's energy reserves are severely limited by his bonding with Kaminaga and use of the Beta Capsule, he possesses limitless energy through the use of negentropy. As Ultraman's energy wanes and the red patterns on his body turn green, his Spacium Beam weakens and Mefilas begins to close the distance. However, Mefilas observes a gold-colored member of Ultraman's species hovering behind him, and abruptly ends his attack. He remarks that matters have been complicated and that this planet is no longer worth killing Ultraman. He agrees to take the Beta Box and leave, then uses his powers to recover it from the chopper before vanishing.
On August 1, 2019, Tsuburaya Productions announced that an Ultraman film helmed by Shinji Higuchi and Hideaki Anno was in the works, produced in association with Toho and khara and set for a 2021 release. Anno had already completed the first draft of the script on February 5. The film will star Takumi Saitoh, Masami Nagasawa, and Hidetoshi Nishijima. A later report from Japanese news outlet Natalie, which featured comments from Higuchi, Saito, Nagasawa, Nishijima, Tsuburaya chairman Takayuki Tsukagoshi, and Toho president Minami Ichikawa, revealed Saito's role as Ultraman's human host, with Nagasawa playing his partner. In his statement, Higuchi remarked that "A baton has been entrusted to me that has been shining ever since I was a small child. I will solemnly strive to fulfill my responsibility to pass on that heavy, radiant baton created by my seniors." On September 25, ten additional cast members were revealed, including names such as Daiki Arioka, Akari Hayami, and Tetsushi Tanaka.
An extraterrestrial silver giant that descends to Earth during a Kaiju rampage, quickly defeating the beast. All-Loving Hero: He protects humanity no matter what, even offering his own life so Shinji can live once again.
A Form You Are Comfortable With: Since his true form is, in a way, unsettling, thanks to its unnaturally large size (at least compared to humans, as he refers to them as "little lifeforms") and his unchanging mask-like face; Ultraman uses a human disguise. Ultraman smiling in Kaminaga's form, something he'd never be able to do in his true form, may be a way for him to put people at ease and show trust.
Beware the Nice Ones: Late in the film, Ultraman threatens that he can bring untold amounts of destruction if he's obstructed from his self-appointed protection of humanity. It is unknown if he was bluffing in the negotiations, but his stoicism truly gave him a Poker Face to dread. Notably, he's the only Extraterrestrial to do this with the Japanese government; Zarab and Mefilas were dishonest with their "peaceful" intentions, and Zoffy only told Ultraman what he was about to unleash upon Earth. Ultraman: I don't get involved with human society. I'm merely an observer. I am not a threat to you. Government Official: Sadly, an overwhelming majority of the international community doesn't trust you. If you can't come with us, with can't guarantee the lives of the SSSP. Ultraman: Intimidation is a terrible thing for a human to do. If you do that I won't hesitate to wipe out the humans before Zetton does. Goverment Official: Isn't that intimidation as well? Ultraman: I am negotiating on equal ground. If you wish for humans to live, please refrain from futile attempts to meddle with the SSSP. Goverment Official: Understood.
Big Brother Instinct: Ultraman sees a kinship with humanity out of curiosity for their varied natures and heroism. Putting his very life on the line in every fight because he sees them as helpless to the horrors of the vast cosmos. Unlike Mefilas, he expresses neither condescension nor disgust at their weakness, nor does he desire to manipulate them. He legitimately feels compelled to protect them. Ultraman: I want to protect these helpless, vulnerable little lifeforms.
Birds of a Feather: If he knew or not is unknown, but he and Shinji Kaminaga seem to share the same heroic and sacrificial spirit. In fact, maybe this is why he decided to take his place. Not only to make amends for his part in Kaminaga's death, but as a gesture of respect in humanity as a whole. Kaminaga's sacrifice may have been the trigger behind Lipiah's interest in mankind.
Blue-and-Orange Morality: In keeping with his alien nature, Ultraman is puzzled by human behavior as much as the Katokutai are puzzled by Ultraman himself.
Crazy-Prepared: He left Asami his Beta Capsule knowing that Alien Zarab would kidnap him, a trace with ink so he could be tracked, contacted one of Shinji's old partners beforehand and filled him in with the info so Asami could rescue him, and also left Yumi an USB with data on the Beta system so Taki could find a way to defeat Zetton in case he wouldn't be able to defeat him himself.
Chronic Hero Syndrome: Even when framed as a criminal in both Earth and his people, he sees his duty as being mankind's protector, against kaiju and extraterrestrial threats. Even if one of his own people demand he surrender himself, he won't abandon mankind. When threatened to not interfere at the risk of his own life, he continues with little hesitation. It is implied this is because of his fusion with a human, but it is ambiguous if this is the case or he grew to care for mankind on his own.
Determinator: Breaking the laws of the Planet of Light, framed as a criminal by Earth laws, feared and hated by both the SSSP Katokutai and humanity as a whole. None deter him from saving as many human lives as he can.
Fusion Dance: Ultraman establishes a connection to the dead Shinji Kaminaga, creating a separate Shinji Kaminaga that is both Ultraman and Shinji. Ultraman-as-Shinji likens this coexistence as something in between a human and the red giant.
Humanity Is Infectious: He asks himself why a human would give his life for the life of a child. So he decides to live among them as a man himself. Because of his studies, he concludes mankind deserves to be protected from the constant threats it receives from aliens and giant monsters. This is a downplayed example, as he doesn't seem to outwardly become more "human" he nonetheless feels compelled to protect them and even wishes to be human himself so he can fully understand their experiences.
Intrigued by Humanity: Ultraman shows a great interest in humanity thanks to Kaminaga's death while trying to protect an innocent. Seeing them as a young species that deserves his protection to grasp them better, he chooses to live as a man in order to analyze their ways and is shown reading their books on philosophy and science. He also seems to respect their resourcefulness, as he never shows hostility to any humans, be they hostile or not. All in all, it is his mere interest that grew into an unconditional love for humanity.
Messianic Archetype: No matter what happens, Ultraman fights in the defense of humanity. Even at the cost of his own life. His kindness towards practically everybody also seems to display messianic vibes. The SSSP and mankind seem to treat him as the last and only line of defense against threats that are insurmountable, likening it to praying to a merciful deity. Ultraman himself regards an idolatry-centered view as a flawed assesment to him, seeing himself as an organism first and foremost. Hiroko Asami: [At seeing phones ringing all around because of Zetton] They just want us to get Kaminaga to do something. Taki Akihisa: They are depending on Ultraman for everything now. Kimio Tamura: Humans have always prayed to gods when they are desperate. Ultraman is the closest thing we have to a god. No wonder people cling to him.
Nerves of Steel: Ultraman never shows fear at any point in the film. Seemingly acknowledging new events as matter of factly. From Zarab's reveal to the final opponent, Ultraman never wavers on his self-appointed guardianship of mankind.
No Social Skills: Naturally, as he is an alien who has just wanted to learn about humans. His first interaction with Asami (as Shinji) is really awkward and robotic; and he doesn't seem to realize there's anything wrong with sniffing around Asami's body to memorize her scent in order to find the Beta Box. He avoids most problems simply by not interacting often.
Normal Fish in a Tiny Pond: Like his television progenitor, Ultraman is not a particularly strong member of the Space Garrison. He struggles against high-profile galactic criminal Mefilas, and while he's unable to escape the pull of a six-dimensional black hole, his commanding officer Zoffy is able to rescue him from it with ease after locating him.
Spell My Name with an S: His true name was originally understood as Ripia (リピアー) before being officially romanized as Lipiah.
The Voiceless: When in his giant form, Ultraman does not vocalise at all, not even the signature battle cries the original Ultraman makes. While he can speak to Mefilas and Zoffy, it's implied that they are communicating through telepathy instead of conventional speech.
Superman Substitute: An interesting aspect, is that either by coincidence or design, Ultraman always had slight similarities to Kal-El from DC comics. The Shin incarnation of Ultraman, on the other hand, seems to be a bit of a Reconstruction of his premise, of being an alien that identifies himself with humanity, willing to protect them all at costs from alien threats. This what is notable for this incarnation is that Ultraman is actually shown why he comes to be mankind's protector, despite never being raised by humanity. His protectorate of them came to be because of one kind man's sacrifice. His interest at first could be considered along the lines of a scientist trying to do research on some sort of primitive civilization. Eventually, Ultraman decrees he's willing to protect them for altruistic reasons (or it was the intent all along). Like Superman, he was even willing to become human, but unlike Superman, who sometimes wishes so he can have a normal life, Ultraman does it out of wishing to have the full experience of being human. From their vulnerabilities to their strength of will. Even if the means for both heroes to love humanity unconditionally are different, the outcome remains the same.
White Sheep: Out of all extraterrestrial life shown in the movie, Ultraman is the only one who has shown concern for those weaker than himself. Going as far as arguing with Mefilas about how mankind should develop as a species. Compared to his superior, Zarab and Mefilas, he seems to be the only alien who actually is willing to empathize with humanity as a whole.