Mari Iwata | The Wall Street Journal

Among the ranks of Japanese who’ve turned against nuclear power recently, one of the unlikeliest converts is Yoshinori Kobayashi, a comic-book artist famous for his right-wing views on Japan’s imperialist wars in Asia.

Mr. Kobayashi is best known for a 1998 manga — or comic book — entitled “Senso Ron” (“About War”). The manga argued that Japanese soldiers fought to protect the country in the years around World War II and that modern Japanese should honor them. It sold more than a million copies and helped foster a rise in Japanese neo-nationalism in the late 1990s, among young people who had previously heard few good things about Imperial Japanese forces.

In late August, however, Mr. Kobayashi deviated from the ranks of most Japanese conservatives with the publication of a manga titled “Datsu Genpatsu Ron,” or “Exit Nuclear Power.” The book is unlikely to be popular with Mr. Kobayashi’s typical readers. The majority of right-leaning opinion leaders in Japan have maintained support of nuclear power even after last year’s accident at the Fukushima Daiichi plant, including the always-controversial Tokyo governor Shintaro Ishihara.

“This will definitely have a negative impact on the sales of my books,” Mr. Kobayashi told JRT. “But I cannot tell a lie to make my living.”

Mr. Kobayashi, who was born in 1953, said his transformation to an anti-nuclear stance was a gradual one. “Our generation grew up reading Astro Boy,” Mr. Kobayashi said. The well-known 1960s cartoon, which was aired across the world, was originally a comic book series written in Japan. The main character is a boy robot named Atom. “He moves on nuclear power, his little sister is Uranium, and his older brother is Cobalt. It was filled with nuclear-related words. I didn’t have any negative feelings about nuclear power,” Mr. Kobayashi recalled.

Even in the wake of the Fukushima accident, Mr. Kobayashi thought the situation couldn’t have been all that serious. But he said that after a few weeks he decided he should reconsider his views, as explanation after explanation by the authorities turned out to be inconsistent or false.

Mr. Kobayashi started reading numerous books on nuclear power and visited areas around the Fukushima Daiichi plant. He said it was particularly painful to see the suffering of Iitate, a town northwest of the Fukushima plant that was bathed with large amount of nuclear radiation carried by the wind. “They had never received nuclear subsidies. But the town was killed. There is nothing worse than that,” Mr. Kobayashi said.

Mr. Kobayashi has a track record of maverick views. He started his manga career as a political satirist in the early 1990s. His first big seller in the political arena was a comic book on the class-action lawsuit brought by people infected with AIDS by contaminated blood products. That work was unpopular with progressives.

Although “Senso Ron” endeared Mr. Kobayashi to nationalists, many abandoned him after he spoke out in favor of a female emperor in 2005.

Mr. Kobayashi said he remains a staunch conservative, adding that whether Japan needs nuclear power or not has nothing to do with ideology. “For me, being conservative is the same as loving one’s home,” he said.

Mr. Kobayashi said he was disappointed with the government after it appeared to backtrack recently on a strategy of abandoning nuclear power by 2040. “You can see the pro-nuclear camp has been regaining support,” he said. “We have to fight tooth and nail, or nuclear plants will come back online one after another.”