A well-known Japanese right-wing activist has denounced recent "hate speech" demonstrations against Korean residents, calling the movement "despicable" and saying it creates a misleading impression of Japan overseas.

"I've been involved in right-wing movements for around 45 years since I was a student, but even looking back, what's happening now is very unpleasant," said Kunio Suzuki, founder and advisor of the nationalist group Issuikai, during a joint press conference with upper house lawmaker Yoshifu Arita on Tuesday.

Mr. Suzuki was referring to a series of anti-Korean rallies organized by a group called Zaitokukai, which has staged demonstrations of 200-300 people, often in the neighborhoods of Shin-Okubo in Tokyo and Tsuruhashi in Osaka, both home to many ethnic Koreans. YouTube footage of the rallies shows demonstrators shouting and waving placards with slogans such as "Exterminate All Koreans."

But Mr. Suzuki said such activities have nothing to do with traditional right-wing movements, and the rallies create the impression that all Japanese are hostile toward Koreans.

"Most right-wingers, conservatives and ordinary Japanese have nothing to do with hate-speech," he said. Issuikai was formed in 1972 as an anti-U.S. political organization that also challenges accounts of past atrocities against other Asians by Japan's military.

Zaitokukai, on the other hand, was formed in 2006 and protests "special privileges," such as welfare benefits that the group claims have been abused by Korean residents, most of whom are descendants of laborers brought to Japan before and during World War II. According to its website, the organization has about 13,000 members.

The heated rallies come as Japan finds itself entangled in rows with China and South Korea over disputed territories, and over Japanese aggression toward Asian neighbors before and during World War II.

Mr. Arita, a lawmaker for the opposition Democratic Party of Japan, said Zaitokukai and its support groups appear to have drastically escalated their campaign since Prime Minister Shinzo Abe and his Liberal Democratic Party returned to power last December. Both the prime minister and his party are well-known for their deeply held nationalist views.

During parliamentary testimony in May, Mr. Abe described Zaitokukai's recent activities as "extremely regrettable." But Mr. Arita said the prime minister needed to be tougher.

He also calls for new laws against hate speech, saying that while Japan has signed the United Nations convention against racial discrimination, it has refused to introduce hate-speech laws.

"We need to debate government regulations (on hate speech) in parliament and think about what we can do under current laws," he said.

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