Merging Western Comics and Anime: An Interview with Batman Ninja vs. Yakuza League Writer Kazuki Nakashima

Batman Ninja vs. Yakuza League is a superhero anime film that takes DC Comics' Justice League of America and reimagines them as yakuza. But that's only the start of how over-the-top this film gets. It's got everything from sudden musical numbers to “yakuza storms”—literal yakuza raining from the skies. To learn more about where these crazy ideas all come from—and the process of merging Western superheroes and yakuza in general—I talked with the film's writer, Kazuki Nakashima of Gurren Lagann and Kill la Kill fame.

Nakashima was first introduced to the world of DC Comics at the age of seven. “My first experience with DC Comics was in 1966, when the [Batman] TV series starring Adam West was being broadcast in Japan,” Nakashima began. “Around that time, I read the Japanese translation of the original American [Batman] comics. I still remember the scene where Batman is given a drug that turns him into King Kong. Looking back, it was a pretty unconventional story, wasn't it?” he laughed. “Shortly before that, I had also watched the Superman TV show starring George Reeves, so I had the impression that DC Comics were about heroes who promoted good and punished evil.”

“This all changed when I encountered Batman: The Dark Knight Returns,” Nakashima continued. “Around 1990, I happened to come across this comic when I was in California for work, and was shocked by how original the story was. It was in the original English, so I couldn't understand it exactly, but the plot of Batman fighting Superman and the realistic tone of the story were fresh to me. My perception changed from that point on, and I was reminded of the depth of DC Comics." Since then, Nakashima has become a fan of other seminal DC Comics like the Alex Ross-illustrated Kingdom Come and Batman: The Killing Joke.

Nakashima got his chance to write his own DC Comics story in the form of the anime film Batman Ninja. After that film was released in 2018, work soon began on a sequel, though it was far different from what we would eventually get with Batman Ninja vs. Yakuza League. “At first, I was thinking of a plot with the Suicide Squad as the main characters. However, the setting I created was very similar to that of another project being developed at DC at the time, so this plot was scrapped,” Nakashima lamented. “I thought about a setting that would not overlap with anything else, and came up with the idea of the Justice League becoming Japanese yakuza.”

In the film itself, each member of the Justice League is twisted into a new, yakuza-fied version of themselves. For example, Wonder Woman becomes a Lady Snowblood-type, Aquaman a fish market-working Isshin Tasuke-type, and the Flash a samurai-era Kogarashi Monjirō-type. This led to interesting interactions between the characters, like between Wonder Woman (Diana) and Aquaman (Arthur).

“When I came up with the idea that Diana was born on Benten Island in Lake Inokashira, I thought it would be interesting if an aquatic human race lived at the bottom of the lake,” Nakashima told me. “Childhood friends fighting each other is a popular plot in Japan. It was an effective way to deepen the relationships between the characters in the short 90-minute runtime.”

But perhaps even more entertaining aspect of the film to come from this merging of yakuza tropes and superhero comics is the sisterly relationship between Harley Quinn and the yakuza-fied Wonder Woman.

“When [my version of] Harley first appeared in Batman Ninja, she was in the position of the Joker's partner, as it had been in Batman: The Animated Series. But since then, in live-action movies starring Margot Robbie, she has mainly been portrayed as an independent character. So I wanted Harley in the Batman Ninja series to attain that same position.” Nakashima explained. “This time, I thought of a story where Harley meets Diana in Hinomoto and gains a perspective on how to live without depending on the Joker.”

Unfortunately, this unlikely friendship looks to end as the credits roll. In Nakashima's own words: “Wonder Woman and Diana are different people, so I don't think it will affect the relationship between Wonder Woman and Harley in the world Batman returns to."

Of course, adapting American comics into Japanese anime is far from a simple task. There is more than a little localization needed to make the story hit home. “There are many different aspects, such as religion and culture. If we follow the original comics exactly, there would be some aspects that we, as Japanese people, would not be able to fully understand—like characters' motivations,” Nakashima told me. “Therefore, I tried to make those aspects as general as possible so they could be understood universally.”

Luckily, with Batman Ninja vs. Yakuza League, this was a relatively simple task. “In particular, in this work, the Yakuza League are Japanese people with the same abilities as the JLA, but who live in a different pocket reality—so I could portray them relatively freely.”

When I asked Nakashima what he thought about his Yakuza League characters and what they can tell us about the essence of their Justice League counterparts, he had a surprising response that gives a unique insight into his view about the role of the author in creating fiction: “I think it's rude for a creator to talk about the essence of a character. What's important is if people can watch the work and feel that on their own."

To wrap up the interview, I asked Nakashima where some of his over-the-top ideas come from. “Sometimes inspiration just comes out of nowhere (like the 'yakuza-storm') and other times it takes a lot of effort to wring it out,” he responded. “At those times, I store away stories, characters, plots, and ideas that I like in a drawer in my head. Then I pull them out and rearrange or combine them, trying to expand them in as unexpected a direction as possible."

Batman Ninja vs. Yakuza League is available to purchase on Amazon Prime Video.