Batman and Catwoman meet Gorilla Grodd in Arkham when the latter activates a mechanism. As a result, the Dark Knight and Selina Kyle find themselves in Japan during the Edo period. It soon turns out that during the time travel, the main villains of Gotham also arrived in the Land of the Rising Sun - Deathstroke, Poison Ivy, Two-Face and Penguin. But the true ruler of Japan is the Joker himself, who, along with Harley Quinn, has now taken control of the island. Batman then goes to his castle to stop the supervillain, but is defeated. Alfred manages to restore Bruce, and with the support of a clan of ninja followers, he decides to defeat the five evil daimyo who agreed with Grodd to return to the present. As legend foretells the arrival of a bat-like warrior who will bring peace, Bruce enlists the support of loyal allies. Together, the heroes of the Batman Ninja anime cartoon will have to stop the Joker's crazy plan and activate Grodd's device in order to return home.