The New Onigashima Project is the name of a military project designed by Kaidou which involves moving the island of Onigashima onto Wano Country's mainland, officially putting it under the Beasts Pirates' control and turning the country into a lawless paradise for pirates in order to oppose the World Government.
Kaidou plans to move his base to the Flower Capital, transform Wano into a pirate nation rechristened as New Onigashima, and have his "son", Yamato, replace Kurozumi Orochi as shogun. All citizens of Wano, including those of the capital, would be converted into slaves in order to provide additional labor for further industrialization of the country. Kaidou, together with Big Mom, also plan to find the Ancient Weapons and One Piece, starting the "final war" against the World Government and its new power.
In preparation for the announcement, Kaidou requested that the Tobiroppo find Yamato.
Kaidou announced this project during the annual Fire Festival held at Onigashima as Kozuki Momonosuke was about to be executed. When Orochi objected to the declaration of his territory being annexed, which was a violation of the terms of their alliance, Kaidou swiftly beheaded him, effectively ending their twenty-five years of partnership. Kaidou then threatened Orochi's subordinates, offering them a chance to join the Beasts Pirates or risk being punished with death. Without hesitation, they swore loyalty to Kaidou.
During the raid by the Ninja-Pirate-Mink-Samurai Alliance, Kaidou proceeded to raise Onigashima from its spot at sea in order to physically transport it to the Flower Capital and drop onto the shogun's castle. Big Mom pointed out that pulling such a maneuver in the middle of the Fire Festival would naturally lead to a huge number of casualties, which Kaidou laughed off since replacing the dead with slaves was a triviality to him. Furthermore, in order to find the One Piece, Nico Robin, the Archaeologist of the Straw Hat Pirates, and possibly the only person alive who knows how to read the Poneglyphs, was requested to be captured alive.