Katsuhisa Fujita was found guilty of forcible obstruction of business and told to pay 200,000 yen (US$1,775; euro1,390), according to an official at the Tokyo District Court, who declined to be named citing policy.

Prosecutors said Fujita asked parents at a 2004 graduation ceremony to remain seated while the anthem was played, and refused to obey school supervisors who told him to stop his appeal and leave, Kyodo News agency reported.

Fujita, already retired at the time, attended the ceremony as a guest.

Fujita's lawyers criticized the case as a crackdown on those who consider the "Kimigayo" anthem and Rising Sun flag symbols of past Japanese militarism. Many teachers say they object to the flag and anthem's militarist connotations.

The flag's and anthem's links to Japan's imperialist wars in Asia during the 20th century prevented them from becoming official symbols until 1999.

A 2003 directive from Tokyo's nationalist Gov. Shintaro Ishihara threatened teachers with punishment for not recognizing the symbols, and the school board has penalized some 300 teachers so far.

Hundreds of public school teachers have retaliated by filing criminal complaints against Ishihara.