A pickpocket lives by reading people who are busy with something else, and 100 Days of Deception hands one the hardest mark there is: an occupying government. Lee Ga-kyung, the best thief in Gyeongseong, as Seoul was called under Japanese rule, is offered a deal by the independence movement. She takes a false name, gets hired inside the Japanese Government-General of Korea, and works as their spy for a hundred days. The Korean period espionage romance, coming to Netflix with Kim You-jung in the lead, is built on that contract and on one detail about the woman who signs it: the cause is not hers. The official tvN teaser is titled with her own line, “I’m going to get to America no matter what.”

The series is tvN’s special project for the channel’s 20th anniversary. Ryu Bo-ri, who wrote Do You Like Brahms?, wrote it, and Yoo In-shik, the director of the Dr. Romantic series and Extraordinary Attorney Woo, directs with Kim Yoon-jin. Studio Dragon and Nangman Crew produce. The story is set in 1932, inside the building from which Japan administered its colony. Ga-kyung walks into it as Geum Seo-hee, a newly hired interpreter, sent by Yoo So-ran (Kim Hyun-joo), a sniper for an anti-Japanese group called Gugukdan. So-ran’s pitch, in the promotional material, is short: “Become our spy. I’m suggesting a deal.”

The complication is a man Ga-kyung has already robbed. According to the Korean press materials, the two first meet when she lifts the wallet of Kim Tae-woong (Park Jin-young, the GOT7 member credited as Jinyoung) at Gyeongseong Station. Inside the Government-General he goes by Sato Hideo: an elite interpreter fluent in Korean, Japanese and English, back in Joseon after a decade abroad, and the adopted son of Sato Shinichi (Jin Seon-kyu), the Director-General of Political Affairs and the second-highest official in the colonial administration. Tae-woong has two names and, by the show’s own description, a mission of his own. One of his promotional lines sums up the first encounter: “Your pickpocketing skills were excellent. Mine were terrible.”

The teaser turns that encounter into the engine of the series. Tae-woong keeps running into Ga-kyung under a different identity, and he asks the obvious question out loud: “A pickpocket, a lodger, now a Government-General interpreter?” His father tells him to make her dependent on him. On the other side, So-ran gives Ga-kyung a new assignment: win Sato Hideo over. The teaser ends with Ga-kyung telling him, “I like you. Since we first met,” while she crosses her fingers behind her back. Both handlers, in other words, have pointed their agent at the other agent.

Read that way, the premise is less a love story with espionage around it than a story about two professional liars working in the one building where a lie could get a Korean killed. An interpreter was the point where the colonial state’s orders became Korean words, and the setup places both leads in that job, where every sentence passes through them and neither side has reason to trust them. The official tagline tells viewers where the arc is meant to go: “It was a lie that lasted 100 days. Until it became sincere.” Sato Hideo’s own poster line runs the same current from his side: “Even though I knew it was a lie, I kept wanting to believe it.”

The year is chosen with care. In 1932 the independence movement carried out its most visible attacks outside Korea: early that year Lee Bong-chang threw a grenade at the Japanese Emperor’s procession in Tokyo, and months later Yun Bong-gil bombed a Japanese ceremony at Hongkou Park in Shanghai. The series drops its fictional sniper, its pickpocket and Yoo Philip (Lee Moo-saeng), a Korean-American correspondent who works for the movement, into that climate. Sato Shinichi’s character poster points straight at it: “Do you really think Korea will gain independence just by killing me?”

Korean screens have come at the colonial period through several doors. The Handmaiden built a con around a pickpocket in 1930s Korea. Phantom hunted a spy among the Government-General’s own staff. The Age of Shadows and Assassination followed independence fighters through double-crosses, and tvN’s own Mr. Sunshine set a romance against the resistance era. Netflix has recently carried Gyeongseong Creature in the same city. What 100 Days of Deception changes, on paper, is the starting motive. Its heroine does not begin as a patriot or a victim looking for revenge. She begins as a professional thief with a ticket in mind, and the premise suggests the drama will measure how much of the cause rubs off on her before the clock runs out.

There is a second clock under the first. The alias Ga-kyung is given, Geum Seo-hee, is not random: in the press materials So-ran reveals that Seo-hee was her daughter’s name. That puts So-ran’s grief inside Ga-kyung’s cover story, so the recruit is carrying her handler’s loss into the building every day she works there.

The casting leans on performers who can hold a double register. Kim You-jung, whose earlier leads include the Joseon-set Moonlight Drawn by Clouds and My Demon, plays the thief who has to sound like a trained interpreter. Park Jin-young plays the son of the regime who may not be what his father thinks. Kim Hyun-joo, seen worldwide in Hellbound, is the handler; Jin Seon-kyu, known internationally for Extreme Job, is the official at the top of the building. Park Jung-yeon and Lee Sun complete the credited cast.

The setup also leaves the obvious question unanswered. If a thief pretends to be a spy for 100 days, and the man she is meant to charm is pretending to be someone else for his own reasons, the deadline does not decide which of them was lying. When the hundredth day arrives, what exactly will Ga-kyung have been loyal to?

100 Days of Deception premieres on tvN on 10 October 2026 at 9:10 p.m. Korea time and streams on TVING in South Korea and on Netflix globally, with new episodes every Saturday and Sunday. The first season runs 16 episodes, with the finale scheduled for 29 November. The characters are fictional; the setting, the Japanese Government-General in 1932 Gyeongseong, is historical.