First of all , by appearing real characters of history , < YongSa - um > intends to infuse Patriotism and National consciousness into the heart of Korean people suffering from Japanese invasion . This is not out of all relation to the fact that Choi Hyun ( 崔 睍 ) , the author of < YongSa - um >, took an active part in loyal troops against Japanese Invasion of Korea in 1592 .