|This article is about a/an subsidiary company in Kamen Rider Zero-One .|
- "Presented by ZAIA"
- ―ZAIA’s copyright slogan[src]
ZAIA Enterprise Japan (ZAIAエンタープライズジャパン ZAIA Entāpuraizu Japan), simply ZAIA or ZAIA Japan, is a subsidiary of ZAIA Enterprise based in Japan. In addition to marketing products for civilians, they are also a weapons developer. They plan to sabotage Hiden Intelligence and dominate the world with their technology.
ZAIA Japan was involved with the production of the prototype Humagears used during the Daybreak Town Accident. They also supply A.I.M.S. with their equipment and Progrisekeys to fight MetsubouJinrai.net and the Magia.
Their proposed solution to an outbreak of Humagears being hacked in masses is the Giger, a series of giant mecha capable of hacking Humagears in masse, though this is turned against them by MetsubouJinrai.net, who take no time to hack into a Giger and produce a massive outbreak.
It was later revealed that President Gai Amatsu was behind corrupting the Ark as a means of corporate sabotage to do a hostile takeover bid of Hiden Intelligence and gain its technology to control the world. After humiliating Hiden Intelligence President Aruto Hiden by causing another outbreak of rampaging Magias on Christmas when he thought he defeated Metsuboujinrai.net, the panicked public and press demanded answers. Gai arrived and posed as a Samaritan, claiming that Aruto was not aware of what Humagears were capable of and that he would declare a takeover bid to seize control of Hiden's stocks and destroy all the Humagears once the bid was accepted by federal regulators.
ZAIA Enterprise Japan succeeded in taking over Hiden Intelligence, leading its former president Aruto has to found HIDEN Manufacturing until Ark-Zero's rampage. ZAIA Japan would later gain a new president in Williamson Yotagaki, who was revealed to be responsible for Jin's revival.
ZAIA Japan would later collapse as the result of the Kamen Rider MetsubouJinrai crisis, its headquarters destroyed in a massive explosion set off by MetsubouJinrai under the delusional belief that it is saving the world by doing so. Gai would attempt to rebuild from the incident with his own startup company, only to encounter Kuroto Dan in the process, whose data had been intercepted and revived by the Ark following his seemingly final death over a year ago.
- Gai Amatsu - First president (demoted to Section Chief of Thouser Department)
- Yua Yaiba - President's assistant, technical advisor and later commander of A.I.M.S. (resigned)
- Williamson Yotagaki - Second president
- Daiki Kyogoku - Chief of Research and Development Department
- Makio Nodachi - Managing director
- Several unnamed ZAIA Japan employees
ZAIA Spec Representatives in the Workplace Competition
- Rentaro Tachibana - Florist
- Tatsumi Arayashiki - Realtor
- Naoto Ichimori - Prosecutor
- Takeshi Homura - Firefighter
- Masamitsu Yuto - Politician
- Ark (co-produced with several other companies)
- Several Progrisekeys
- A.I.M.S. Shotriser
- Attache Shotgun
- Attache Arrow
- ZAIA Thousandriver
- Thousand Jacker
- ZAIA Spec
- Humagears (Autonomous Type)
- ZAIA Slashriser
- ZAIA Pants
- Main article: Raiders