Osaka Mayor and Nippon Ishin no Kai (Japan Restoration Party) chief Toru Hashimoto plans to sue the weekly Shukan Asahi and daily Asahi Shimbun, claiming they violated his human rights when the magazine ran an article six months ago touching on his family background.

“Freedom of the press and freedom of expression are the basis for democracy, so I’ve been quiet. Since becoming a public official, I’ve respected press freedom. But I’m taking legal procedures against Shukan Asahi,” Hashimoto tweeted Saturday.

Last October, the magazine ran a cover story by a freelance nonfiction writer who noted Hashimoto’s father had been a member of the yakuza and came from an area in Osaka traditionally associated with descendents of the “burakumin” feudal-era outcasts. The article was supposed to be the start of a series exploring Hashimoto’s rise.

The article broke no new ground, repeating what similar stories had said in other magazines in fall 2011 just before the simultaneous Osaka gubernatorial and mayoral elections.

But Hashimoto attacked the Shukan Asahi and Asahi Shimbun, its parent company. The magazine’s president resigned, a third-party panel convened by the Asahi Shimbun group agreed the article was discriminatory, and the series was canceled.

The magazine also apologized to Hashimoto, and the matter seemed resolved until last week.

An article in the April 12 edition of Shukan Asashi, quoting anonymous sources, said Hashimoto is growing less and less interesting as a television news topic, and now that Prime Minister Shinzo Abe’s economic policies, including his vow to pursue massive public works spending, are proving popular, Hashimoto, who strongly believes in cutting public works and privatizing where possible, was nearing his “expiration date” as a politician.

Hashimoto tweeted displeasure over last week’s article but said the legal steps were only for the article that ran six months ago.

“A lot of people probably thought my charges against the Shukan Asahi and the Asahi Shimbun were finished. I accepted the magazine’s apology. But (the question of) seeking damages is a different (issue) because the Asahi made a lot of money off that story,” Hashimoto said.