This study aims to explore diachronic changes of close kinship terms such as father, mother, uncle, aunt, son and daughter in North Korean English textbooks as to how the metaphorical extensions of these words occur. To this end, this paper uses North Korean English textbook corpora from 1991 to 2015 and AntConc, a corpus analysis tool employed for the investigation of these close kinship terms with their co-occurring lexical context. The findings are: Most frequent metaphor in the 1990s is the head of state as father and its people as sons and daughters. The metaphor of sons and daughters persists in the textbooks of 2000s, but not the head of state as father. Father stops with Kim, IlSung in its metaphor. In 2010s, father, sons and daughters metaphors have disappeared, though other metaphors remain in fatherland, motherland and mother tongue. The engineered metaphors such as father and sons/daughters by the state tend to be easily forgotten due to its forced nature of these expressions. This disappearance of metaphor shows a critical difference of metaphorical endurance between naturally occurring metaphors and artificially formulated metaphors.