If the Japan Restoration Party — headed by Toru Hashimoto, the mayor of Osaka, and former Tokyo Gov. Shintaro Ishihara — needs a new political slogan, the proverb Kuchi ga wazawai no moto (The mouth is the source of great trouble) would do nicely.

Both leaders have a habit of making offensive statements that attract attention and disdain — and generate long press conferences.

Ishihara, now 80, is best known for remarks that offended women, foreigners and minorities — such as 2001’s, “It’s useless and a crime for women to go on living after they (get old and) lose the ability to breed children.”

As if to show he was learning from his senpai (superior), Hashimoto, 43, put his foot in his mouth in May, first by trivializing the suffering of sex slaves in wartime Japan and its occupied territories, then by opining that U.S. soldiers in Okinawa would benefit from using Japan’s legal sex parlors. For a certified barrister, it was very sloppy oratory.

However, at a May 27 press conference attended by 396 reporters at the Foreign Correspondent’s Club of Japan in Tokyo, he managed to redeem himself just a bit.

There, he strongly condemned Japan’s use of military brothels before and during World War II, saying the nation owed a sincere apology to the Korean, Chinese and even Japanese “sex slaves” savaged by the system. It was almost a complete turnaround from his earlier remarks defending the brothels as a “necessary evil” in wartime.

So, perhaps Hashimoto wins points for condemning the sexual slavery in Imperial Japan. And as regards him recommending U.S. troops use Japan’s legal sex shops — well, it’s just possible his thrust was lost somewhat in cultural translation, resulting in him being misinterpreted to a degree.

Hashimoto knows a lot about Japan’s sex industry — certainly more than most of his compatriots, let alone others. Indeed, he has not contested claims by the Weekly Bunshun magazine that he frequents high-end hostess clubs, where he is a fan of engaging in “costume play” with workers there.

Hashimoto told reporters last month that “anyone could understand” brothels were needed for front-line soldiers facing possible death. He also stated that if U.S. troops made more use of Japan’s local and legal adult-entertainment services, the number of sex crimes committed by them would go down.

He isn’t the only high-profile person to have made this politically incorrect point. In 1995, U.S. Navy Admiral Richard Macke was fired for suggesting that three servicemen on trial in Okinawa should have paid for sex instead of raping a 12-year-old girl. Of their actions, he stated then, “I think it was absolutely stupid. I have said several times: for the price they paid to rent the car (used in the crime), they could have had a girl.”

In Japan, any sexual service — including oral and simulated sex — is legally available. The sex industry is huge, with many subgenre outlets such as “image clubs,” where the women dress up in line with its theme — as nurses, schoolgirls, furry animals, etc. There are also those hostess clubs, strip-shows, touchy-feely pubs and more.

However, prostitution is illegal in Japan — but in most cases only the pimp or brothel owner can be arrested, making it a crime without punishment for the customer and the sex worker. In certain cases, even intercourse can fall into a gray zone of “free love” legality if, for example, a “soaplands” client pays to be bathed before repairing to another room where he and the worker “fall in love” and consummate that feeling, notionally without a further fee being paid.

Many Japanese feel that fūzoku (adult-entertainment services) play a role in combating violent sex crimes, as desires can be satisfied with cash instead of violence.

It’s also a huge part of the economy. The sexual-massage market alone is believed to total ¥678 billion a year.

Hashimoto’s suggestion that if American forces used Japan’s legal sex parlors it would help ensure they let off steam without breaking the law was condemned as “outrageous and offensive” by U.S. State Department spokeswoman Jen Psaki.

Some commentators mistakenly assumed Hashimoto was advocating prostitution — but he would hardly do that, since it’s illegal. Well, yes and no, because getting a sexual massage is not — unlike in most of the U.S.

So, attitudes to the sex industry aren’t just cultural differences between Japan and the U.S. — they’re legal ones, too. But at the time of his earlier remarks, the shyster Hashimoto appeared not to understand either point. Thus, trouble.

In his half-assed apology to the U.S., the mayor noted that “cases of sexual violence in the U.S. military are frequent and have become part of the national conversation in the United States. I suggested to a senior U.S. officer that maybe one way to deal with this would be to consider letting servicemen use the legal adult-entertainment services in Okinawa.”

Then, adding that he wasn’t advocating prostitution, he concluded by urging Japan’s legal sex industry to take measures to protect the dignity of those working in the field.

It is rare for a Japanese politician to address the rights and welfare of current sex workers publicly, which Hashimoto did then. But his motives may not be purely idealistic.

Hashimoto spent several years early in his career as an adviser for a consumer-loan company that was accused of predatory lending practices. He also served as an adviser to a business association in the red-light district of Osaka. Questioned about any involvement the group may have in the sex industry, he avoided going into detail by mentioning attorney-client privilege, and stated twice: “If they were involved in something illegal, the authorities would have cracked down on them” — so deftly evading the issue.

Hashimoto’s first set of remarks gave him the appearance of being insensitive to the “working woman.” Clearly that’s not the case.

Meanwhile, with Upper House elections looming in July, recent surveys have found that voters’ support for the JRP has fallen to an all-time low of 3 percent. Though the data was not broken down along gender lines, it seems increasingly likely it is losing the support of Japan’s female voters. Certainly Ishihara and Hashimoto appear to be poster boys of sexual discrimination.

Hashimoto’s Tokyo press conference may have been an effort to both quell international criticism and also establish him and the JRP as taking women’s issues seriously. They probably didn’t succeed.

However, among women working in the red-light districts of Osaka, at least, this champion of “dignity” for sex workers probably earned some new fans that day.