|This article is about a/an ongoing operation in Kamen Rider Gaim.|
Project Ark (プロジェクトアーク Purojekuto Āku) is a top secret operation planned by the Yggdrasill Corporation. After Overseer Takatora Kureshima revealed the truth behind Helheim to Kouta Kazuraba, he assured Mitsuzane that he did not inform him about Project Ark, that it was top secret along with the Scalar System and he would not tell an outsider about them.
It is later revealed by Ryoma Sengoku that the project would allow them to make one billion Sengoku Drivers in the next 10 years. The entire Human population of Earth is seven billion, which would mean culling out 6/7ths of the population and distributing Sengoku Drivers to the last one billion as a last ditch effort to save all of mankind.
Following the full-scale invasion of Zawame City by the Inves, starting with the infestation of Yggdrasill Tower, Ryoma Sengoku revealed the details of Project Ark to the world after the executives of Yggdrasill's international branches threatened him with an investigation and possibly arresting him for the events happening in Japan. The unveiling of their plan to cull 6/7ths of the world’s population had the company labeled as a terrorist group by the United Nations and news reporters and forced the resignation of all of Yggdrasill's executives worldwide. This event also seemed to have ripple effect as reporters stated that the New York Stock Exchange had come to a standstill and was causing a domino effect that was collapsing the world economy with Yggdrasill's corporate infrastructure in shambles. It also involved the governments of the world, as many high ranking officials who were working secretly to aid Project Ark were impeached or forced to resign.
- Project Ark is not to be confused with the ARK Project, a robot engineering project headed by Dr. Nobuhiko Komyoji, a former colleague of Professor Ryoma, which was referenced on a computer display in the episode The Red and Blue Kikaider, a special crossover episode promoting the movie Kikaider REBOOT.
- In episode 36, while battling against Takatora/Zangetsu, Mitsuzane/Zangetsu-Shin claimed that he was trying to reactivate Project Ark via his alliance with the Over Lords. Though it was unknown how he would do it, but it can be presumed that the method might probably was via the Helheim invasion.