A Japanese film about an ethnic Korean family torn apart by a program to send people to communist North Korea debuted Saturday in South Korea, a poignant tale for a country where millions in the South also remain separated from family members in the North.

"Our Homeland," directed by Yang Yonghi, is based on her reunion with a brother who was sent from Japan to North Korea at age 16 by their father who believed his son would grow up there enjoying fairness and affluence deemed hard to achieve in Japan because of social and ethnic barriers.

The movie tells the story of Sungho, who after moving to North Korea under the program, returns to Tokyo for the first time in 25 years. His reunion with his family is interrupted when he is abruptly ordered back to Pyongyang without getting his scheduled operation for a brain tumor untreatable in North Korea.

Yang's film shines a light on an ill-advised program that sent more than 90,000 ethnic Koreans from Japan to North Korea between the late 1950s and the early 1970s.

"Our Homeland" stars Sakura Ando as Rie, Korean Japanese director Yang's alter-ego frustrated with her inability to stop her brother from being taken away back to North Korea and infuriated at a North Korean agent who tails her brother around. The brother, played by Arata Iura, remains sulky throughout what was supposed to be a three-month stay in Tokyo and makes a poor attempt to recruit his sister as a spy in one scene.

After making a world premiere in Berlin in February, the film is now moving to South Korea's Busan International Film Festival, where organizers say the director was able to secure funding for the production last year.

Kim Ji-seok, a film critic and a festival director at Busan, said "Our Homeland" is essentially a story about a "Korean diaspora" further troubled by political differences.

Kim said that the group of ethnic Koreans who moved from Japan to North Korea under the repatriation program represent "a minority of a minority" and that "Our Homeland" does a superb job of casting a light on the difficult and sometimes forgotten subject.

The repatriation of Japan's ethnic Koreans — many of whom had been forcefully moved to Japan when Tokyo colonized the Korean Peninsula in the early 20th century — marked a rare chapter of cooperation in the history of relations between North Korea and Japan. It provided a much-needed source of labor for Pyongyang and eased a welfare burden for Tokyo, according to Tessa Morris-Suzuki, Japanese history professor at the Australian National University.

The repatriation, however, caused deep suffering for immigrants, since those in North Korea couldn't freely communicate with their relatives in Japan and those remaining in Japan felt anxious about the fate of their loved ones in the North, she said in a 2009 paper.

To make matters worse, the so-called returnees were considered lower in social ranks and even as spies in North Korea, she said.

One of the most conspicuous roles in the movie is played by Yang Ik-june, whose staunch apparatchik-like behavior as an agent slowly softens as he begins to sympathize with the family. He later acknowledges to Rie that he and his brother have no choice to live under orders from the government in Pyongyang "until the end of their lives."

"Our Homeland" was selected earlier this year as Japan's entry for the 2012 Academy Awards best foreign language film.

It is also one of three films in Busan that have to do with North Korea along with "Comrade Kim Goes Flying," a joint North Korean-European production about a young female coalminer with aspirations to become a trapeze artist, and "Choongshim, Soso," a South Korean-made film about a North Korean defector hiding in China.

Yang is the director of two documentaries, "Dear Pyongyang" in 2005 and "Sona, the Other Myself" in 2009 — both of which are based on the her interaction with her family in North Korea.