Japan Teachers Union (日本教職員組合 Nihon Kyōshokuin Kumiai, JTU), often just called "Nikkyoso" (日教組 Nikkyōso), is Japan's largest and oldest labor union of teachers and school staff. The union is known for its critical stance against the conservative Liberal Democratic Party government on such issues as Kimi ga Yo (the national anthem), the Flag of Japan, and the screening of history textbooks since its near continuous one-party rule since 1945. It is affiliated to the trade union confederation Rengo. It had 290,857 members as of December 2009.