[4] The highest status is accorded to those descended from participants in the resistance against Japanese occupation during and before World War II and to those who were factory workers, laborers, or peasants as of 1950.

B. R. Myers, associate professor of international studies at Dongseo University in Busan, South Korea, summarizes the core (haeksim)[5] class as consisting of "high-ranking party cadres and their families".

[6] According to CIA analyst Helen-Louise Hunter, the Communists were highly successful in turning the pre-revolutionary social structure upside down, and songbun is reflective of that.

Kim Il Sung, afraid that Beijing would also interfere in his country, whether by invading or sponsoring a coup d'état (Chinese soldiers had been sent previously on "provocative incursions" into Korea), aimed to increase internal security by classifying his citizens.

[8][page needed] U.S. journalist Barbara Demick describes this "class structure" as an updating of the hereditary "caste system", combining Confucianism and Stalinism.

As a result, one's ability to obtain goods from the distribution system, where one could live, what career was pursued, or how much one could advance in society depended solely on their songbun, which made it the "single-most important factor that determined the life of a North Korean".

Ko was born in Osaka, Japan, which would make her part of the hostile class because of her Korean-Japanese heritage; furthermore, her grandfather worked in a sewing factory for the Imperial Japanese Army.

[17] The building of a cult of personality around Ko encounters the problem of her bad songbun, as making her identity public would undermine the Kim dynasty's pure bloodline.