Dear Pyongyang: The impossible personal and political quandaries experienced by ethnic Koreans living in Japan find gentle, touching expression in Yang Yonghi’s documentary, “Dear Pyongyang.” The director’s father, Mr. Yang, lives with his wife in Osaka, and both remain impassioned supporters of North Korea. YANG Yeong-hui states her astonishment at her parents’ convictions more in her constant first-person voiceover narration than directly with her father. Respect for elders being at a high premium in Korean culture, one can’t expect nor demand familial confrontations, but what is captured will draw strong fest interest and tube viewers in Japan and South Korea. Leaders in the pro-Communist “Zainichi” movement of Korean-born residents in postwar Japan, the Yangs’ belief in a unified, socialist Korea remained solid into the 1970s, when they agreed to send their three sons to the North as so-called “returnees” to the homeland. Two of the filmmaker’s visits to her brothers are shown here, revealing a happy home life, but a truly dreary Pyongyang. The daughter makes clear that the distant kin have avoided hunger and illness thanks only to Mrs. Yang’s generous, regular care packages.