No. of episodes: 16
Genre: Historical, Romance, Comedy
Native Title: 백일의 낭군님
Original network: tvN, Netflix
The drama is set in the Joseon era, Lee Yul (EXO’s Do Kyung Soo) is a cold and demanding Crown Prince. He witnesses how the killing of innocent people land him to be the King’s son and he hated the fact. Lee Yul, a mere young boy fell in love with a noble girl Yoon Yi Seo (Nam Ji Hyun), and set his mind to marry her. But the greed of the adults turns her family into traitors and ordered to kill.
Yi Seo grew up with another identity, Hong Shim a peasant living frugally in a small village far from the capital. Her adoptive father Yoon (Jung Hae Kyun) took her in and they became a family.
Order to marry
The entire kingdom blamed the crown prince for the drought season and want him to spend a night with the Crown Princess Kim So Hye (Han So Hee). Lee Yul hated So Hye as it is a political marriage and she is the daughter of the killer that turned Yi Seo’s family into traitors without evidence.

Lee Yul turns the table around and creates a new law that states any individual that is above20 years old must get married. That law passed and affects Hong Shim who is 28 years old and single. She is also the oldest unmarried woman in Joseon.
What goes around, comes around

The assassination of the Crown Prince led him into Hong Shim’s house. Yoon took the badly injured Lee Yul back home and nurse him to health. To save her daughter from punishment, Yoon took advantage of Lee Yul who developed amnesia and trick him to say he was the fiancé that Hong Shim is waiting for.

Lee Yul and Hong Shim got married and became a couple with the name. Even though he forgets his identity and where he lives, his behavior did not change. Putting his nose high up, he wanted everything and only the best thing. Not knowing how commoner lives struggling day by day, he was conned into borrowing a huge sum from a loan shark.
Village idiot

After marriage, Lee Yul brought only more troubles to Hong Shim and Yoon. The amount of debt he owed is significant and the last thing Hong Shim wants from him is to leave the house and fear more troubles will follow him home. The entire village took him as an idiot with only looks, no experience in any hard labor, and can’t help the family to earn a penny.
100 days later
The politicians finally trace him down and found Lee Yul survived in a village. By then, Lee Yul and Hong Shim fell in love and both of them wanted to lead a normal life together. He chooses to be illiterate to fit his new identity and understand why Hong Shim does that too.
Hong Shim reunited with her long lost brother and decided to stick together, the condition is to move around the country as they supposed to be dead. Yoon and Lee Yul agree to go with Hong Shim and his brother but Lee Yul was found and escorted back to the palace.
Bits and pieces of his memories are back but yet to fully recover. He have to start from zero to investigate and find out the whereabouts of Hong Shim. Will Hong Shim’s family name get restored? Will a traitor’s daughter and crown prince have happy ending?

The drama was first aired in 2018, the romantic comedy that quickly gain good reputation for EXO’s D.O. Do Kyung Soo as an actor.