© TVN

She was planning to leave Korea and start over in America. Instead, she has 100 days to live under a false identity inside the headquarters of the very government she hopes to escape.

That is the premise of 100 Days of Deception (100ilui Geojitmal, 100일의 거짓말), a Korean period drama that brings espionage and romance together in 1930s Gyeongseong. At its center is Lee Ga-kyung, a gifted pickpocket whose talent for taking what she needs suddenly becomes useful to the Korean independence movement. The problem? Her mission places her close to someone she may not be able to deceive.

What Is 100 Days of Deception About?

© TVN

Why Gyeongseong Matters

© TVN

Gyeongseong was the name used for Seoul during Japanese colonial rule. In 100 Days of Deception, the city is more than a period-drama backdrop: where people live and which institutions they can enter help explain the world Ga-kyung must navigate.

For viewers curious about that setting, tvN has created an online exhibition with the Seoul Museum of History. One section looks at how the neighborhoods north and south of Cheonggyecheon developed differently under colonial rule. It offers useful historical context for the drama’s streets and power structures without asking viewers to treat a fictional story as a history lesson.

You do not need to know this history before pressing play. But learning a little about Gyeongseong can make the stakes of Ga-kyung’s disguise clearer: she is crossing boundaries shaped by far more than her own choices.

A Romance Built Around Secrets

© TVN

The hook is not simply that a spy falls in love. It is that Ga-kyung cannot easily separate her feelings from her assignment. Hideo works within the colonial government she has entered under false pretenses, and he has secrets of his own. Their growing connection creates a question that a straightforward romance would never have to ask: how much of yourself can you reveal when honesty could endanger everything?

That makes 100 Days of Deception an intriguing pick for viewers who enjoy historical K-dramas but want a story driven by immediate choices, shifting loyalties, and a deadline. The 100-day mission gives the plot its clock; Ga-kyung’s relationships give every decision a personal cost.

Kim Hyun-joo also stars, alongside Kim You-jung and Park Jin-young. If you are starting the series fresh, the best approach is to go in knowing the premise and let the characters reveal the rest.

Where Can You Watch It?

© TVN

100 Days of Deception is listed on Netflix. Search for its official title, even if you first heard about it as 100ilui Geojitmal.

Come for the undercover mission. Stay for the difficult question beneath it: when everyone is hiding something, what would it take to believe someone?