From December 1941 to August 1945, Hong Kong experienced the darkest years in history. Those 3 years and 8 months have become the collective memory of the nightmare of Hong Kong people... This war in Hong Kong is An important part of the Eastern battlefield during World War II is a history that should not be forgotten, a dark period of sad history... The TV series Qiu Chan is a youth spy drama based on this history, It tells the passionate story of the patriotic young Ye Chong and other underground party comrades fighting for the victory of the War of Resistance in those isolated island years.

Helan Mingyu, a bright young woman, forms a deep bond with the 9th Prince, Xiao Chengxu. Though they develop mutual feelings, fate intervenes—news of Chengxu’s death on the battlefield forces Mingyu to marry his older brother, King Xiao Chengrui. As Chengxu achieves military victories that strengthen the kingdom, Chengrui grows increasingly jealous. When the truth about Chengxu's mother's death emerges, Chengxu sets out to claim the throne and seek justice.

The film tells a story of 2 girls who were born on the same day and unintentionally switched at birth. Their lives are completed changed due to the misplacement when they are returned to their respective families.