A man takes his pet African spurred tortoise called Lupin for a walk during a heatwave in Tokyo, Japan on July 3, 2022. (Photo by Masatoshi Okauchi/Rex Features/Shutterstock)

White-robed men hold up flaming torches during an annual fire festival at the World Heritage-listed Kumano Nachi Taisha shrine in the Wakayama Prefecture town of Nachikatsuura, western Japan on July 14, 2022. (Photo by Kyodo News/Newscom/Avalon)

British actress Millie Bobby Brown and Danish actor Mads Mikkelsen break the sake barrel during the opening ceremony for Osaka Comic Con 2023 at the Intex Osaka on May 5, 2023 in Osaka, Japan. (Photo by Jun Sato/WireImage)

A firefighter works outside of a building where an explosion and a fire broke out in Shimbashi area of Tokyo on July 3, 2023. (Photo by Yuichi Yamazaki/AFP Photo)

Japanese professional wrestler Hiromu Takahashi attends a promotional event of a dinosaur show “Dino Safari Gigant” in Tokyo on Wednesday, August 2, 2023. A dinosaur show using dinosaur shaped mrchanical suits will be performed in Yokohama from August 10. (Photo by Yoshio Tsunoda/AFLO/Rex Features/Shutterstock)

Minoru Suzuki and Sanshiro Takagi, wrestlers from Japanese professional wrestling promotion DDT Pro-Wrestling, fight inside Tokaido Shinkansen bullet train from Tokyo to Nagoya during a wrestling show in Japan on September 18, 2023, in this handout photo released by JR Tokai (The Central Japan Railway Company). (Photo by JR Tokai/Handout via Reuters)

Only after World War II did the secret spill: Ōkunoshima, located in the Inland Sea of Japan between Hiroshima and Shikoku, was the top-secret site for manufacturing chemical warfare. When the factories were closed down, a number of exotic wild rabbits were seen freely roaming the island. They were assumed to have been the test subjects for the chemical weapons, which the military failed to eradicate when the factory was demolished.

Dancers dressed as futuristic characters perform during a show at The Robot Restaurant on June 29, 2014 in Tokyo, Japan. The now famous Robot Restaurant opened two years ago in Kabukicho area of Shinjuku at an estimated cost of 10 million U.S. dollars. Performances are held three times a day and cater mostly to foreign tourists. The cabaret style shows include bikini clad futuristic dancers, performers dressed as robots and a host of large scale robots and vehicles controlled with remotes by stage hands dressed as Ninjas. (Photo by Chris McGrath/Getty Images)