"Illishine" is a legendary creature that has existed in the Baek family for a very long time. Hong Soorim has been imprisoned for ten years. When he reached the age of 20 and the mark appeared on his body, the Company that raised Soorim tried to make a deal not only with Chairman Baek but also with Chairman Baek's son, namely Baek Wookyung. Baek Wookyung paid a higher price than Chairman Baek and met with Hong Soorim. Soorim accepts his situation and tries to live his life by taking advantage of Wookyung.
However, Wookyung felt tempted by the presence of Soorim, who was much younger than him.