In 1347, the French port city of Calais on the Strait of Dover was surrounded by the English king's army, but continued to resist for 11 months.
The English king, Edward III, was growing impatient and insisted that if they continued to resist, he would kill all the citizens, but the prince convinced him that he would not be able to win the hearts of the people this way and decided to take six representatives of the citizens as hostages, the king made concessions.
After know about it, Iris's father offered himself as a hostage as one of the prominent citizens. However, his wife was gravely ill, and Iris decided to save her father from the hostage for the sake of her dying mother.
However, when she made her way into the enemy camp, she could not abandon the young man lying on the ground in the rain, and saved him.
The young man fell in love with Iris while she was taking care of him.
This young man was the Black Prince, the hated prince who had captured her father.
Iris, unaware of this, waits until the young man falls asleep and then sets off to find her father in the enemy camp.