Batman Ninja opens with Gorilla Grodd running his latest tech invention, a time travel device, inside of Arkham Asylum. The cape crusader tries to stop him but is unsuccessful and travels back in time to feudal Japan. Immediately Batman comes face to face with samurai jokers and later with the Joker himself and Harley Quinn.
He has to come to terms with the fact that much of the technology he relies on will soon be useless. It takes a bit for this to happen but when the cape crusader finds Robin, Nightwing, Red Hood, Alfred and others allies who are stuck in feudal Japan too it gives him the will to find alternate means to combat Joker and the rest of Gotham’s villains.
The only questionable part of the film is a scene sometime after a big explosion where Joker and Harley Quinn are farming land seemingly unaware of who they are. Red Hood finds them and rapes Harley and tortures the Joker before the cape crusader stops him.
Other wise I feel Batman Ninja has many fun elements and I also like the nods to anime and Japanese culture mixed with the DC character’s origins and history. As well as the second half with the nods to Voltron and similar cartoons too.