A teachers’ union on Wednesday criticized a right-leaning civic group for making complaints against a Seoul high school principal for organizing an outing to watch "12.12: The Day," a film about military dictator Chun Doo-hwan's rise to power through the 1979 coup.

The civic group, called the Freedom Korea National Defense Corps, has accused the principal of abusing his authority, which is stipulated via Article 123 of the Criminal Act, according to the Korean Teachers and Education Workers Union.

"12.12 (The military coup) is an important historical event that is included in the state education curriculum, and it is only natural for a school to help students decide for themselves what to think (of the coup)," the KTU said in a statement, voicing opposition against some right-leaning groups that expressed disdain toward the movie.

The KNDC, along with right-wing YouTube channel HoverLab Inc., claimed that the movie imprints on the audience a "distorted view of history" through what they claim is an inaccurate depiction of the event. They held a protest last Wednesday at a Seoul-based middle school that were going to show the movie to its students.

Several schools had planned to organize viewings, but canceled after the protest.

Another group of school teachers in Korea released a statement last Sunday and berated them as "infringing upon the constitutional right to learn." The KNDC filed charges of defamation against the group.

The 1979 coup, led by then-Army Gen. Chun, has been defined as a rebellion in a landmark 1997 Supreme Court ruling. For his part in the revolt, along with the bloody crackdown of pro-democracy activists in 1980, corruption and other charges, Chun was sentenced to a lifetime in prison -- he had initially been sentenced to death -- for which he was later pardoned.

"12.12: The Day" depicts the night of the military coup and the events leading up to it, focusing on the confrontation between Chun and Gen. Jang Tae-wan, then-leader of the Capital Defense Command who struggled to thwart the rebels from taking control of the military. Hwang Jung-min and Jung Woo-sung plays Chun Doo-gwang and Lee Tae-shin, fictional characters based on Chun Doo-hwan and Jang Tae-wan.

On Sunday, Prosecutor General Lee One-seok watched the movie with several high-ranking officials from the Supreme Prosecutors' Office.

"We should never forget the democracy that we have right now has been made possible through sacrifice and hard work of the Korean people," he said after the film.