OSAKA - Voices of protest have risen Wednesday in Osaka, western Japan against Toru Hashimoto, the mayor of Osaka and co-leader of Japan's opposition Nippon Ishin no Kai (Japan Restoration Party), for his positive stance on the so-called " comfort women."

Apart from the issue of whether the women were coerced or not, Hashimoto said in the municipal office Monday that he believed the system to recruit women into sexual servitude was "necessary to maintain discipline" in the Japanese military during World War II, according to several local media reports including the one by the daily Mainichi Shimbun.

The reports also noted that Hashimoto, also a lawyer, revealed to local reporters that when he visited a US military base in the southern Japanese prefecture of Okinawa earlier this month, he proposed that US troops make "more" legal use of the local sex industry to help reduce rapes and other assaults that have often been reported there.

Following the statements, the JRP's other co-leader, Shintaro Ishihara, supported the remarks Tuesday by saying to reporters in Tokyo that prostitution is a natural product of an army, and that this principle has been widely observed through history.

Ichiro Matsui, secretary general of the JRP and Osaka governor also defended Hashimoto's opinion.

After those political views were widely reported, a spokesperson for Osaka City told Xinhua that the municipal government's various offices have received, as of around noon on Wednesday, more than 400 complaints and message of protest, including e-mails, that have come in from around the country against Hashimoto's statements.

The spokesperson added that most of the messages say the official comments are inappropriate for a mayor or political party leader to make.

The daily also cited representatives of human rights organizations and academic specialists who said the comments encourage the use of sex in order to carry out wars and disparage woman in general. Others said that although the facts surrounding the comfort women system could be researched in greater detail, the mayor's repeated statements on his views is extremely rash for the leader of a national party. ?

The city's spokesperson said the number of messages sent to the municipal government and its branch offices are expected to increase as reports continue to come out while international reactions and condemnations to the comments have also arisen, especially in neighboring countries.