Osaka Mayor and deputy leader of the Japan Restoration Party Toru Hashimoto speaks in Tokyo. (Toru Yamanaka/AFP/Getty Images)

During World War II, Japanese troops forced tens of thousands of women in China, Korea and Southeast Asia into sexual servitude as "comfort women." That phrase still provokes outrage across Asia, in part because Japanese politicians have wavered in taking responsibility for the abuse and, as Prime Minister Shinzo Abe did in 2007, have even argued that the women were prostitutes or otherwise voluntary participants.

On Monday, Osaka Mayor Toru Hashimoto, who is also a rising star in Japan's nationalist political circles, added to the ongoing controversy. He argued that the "comfort women" system was "necessary" for the morale of Japanese troops. His comment has caused wide offense on two levels: for calling such a severe abuse "necessary" and for apparently arguing that the morale of Japan's soldiers, who devastated much of Asia, superseded the rights of Asian civilian women.

“To maintain discipline in the military, it must have been necessary at that time,” Hashimoto said. “For soldiers who risked their lives in circumstances where bullets are flying around like rain and wind, if you want them to get some rest, a comfort women system was necessary. That’s clear to anyone.”

In an unusual step and despite his otherwise offense-giving comments, Hashimoto did acknowledge that the women were conscripted into sleeping with Japanese soldiers "against their will," adding: "The responsibility for the war also lies with Japan. We have to politely offer kind words to [former] comfort women."

The comments were controversial in Japan as well, drawing condemnation from other Japanese officials (the education minister said they "came at a bad time") and from regular Japanese Web users. But, online at least, a number of the comments seem to cheer on Hashimoto, seconding his view that the practice had been "necessary" and scolding Korean or Chinese people who have taken offense.

Many of the Japanese social media comments about Hashimoto's statement, collected and translated by the great news site JapanCrush, are too vulgar to reproduce here. But here are a few representative comments from Hashimoto's supporters, some edited for profanity:

In spite of the fact that they were professional prostitutes who wanted to do it, and they got paid, they turn around and play the victim.

Japan made provisions for comfort women mainly using Japanese women who were highly-paid, and not forced, but the outrageous behaviour of Korea in Vietnam knew no bounds. It’s Korea that needs to reflect on their behaviour and pay reparations.

You know, you really don’t have to report every little thing the mayor says.

Japanese Web critics of Hashimoto's comments seemed mostly to condemn his right-wing politics and mock his understanding of history:

At any rate, Hashimoto is too loose with his remarks. As a politician he’s dangerous and too unstable.

This is a good chance for all those people backing Hashimoto and the Restoration Party to rethink things.

Why is this stupid person talking about this stuff now? There are so many more important things he should be talking about, and yet he does nothing about them.

Though we in the United States might associate young Web users with liberal politics or left-leaning libertarianism, a number of prominent Web forums in Japan are dominated by right-leaning nationalists known as the netouyu. That may help explain why social media commentary in the country can sometimes lean toward nationalism.