100 Days of Deception is tvN’s big 20th-anniversary period spy romance, and it premieres tonight, October 10, 2026, with Kim You-jung and GOT7’s Park Jin-young (Jinyoung) in the leads. Set in 1932 Gyeongseong (today’s Seoul), it follows a pickpocket who goes undercover inside the Japanese colonial government for 100 days. Here is everything you need to know before episode 1, including the cast, the schedule and how to watch it from outside Korea, with no spoilers.

What Is 100 Days of Deception About?

The story follows Lee Ga-kyeong (Kim You-jung), described as Gyeongseong’s best pickpocket and con artist. She dreams of earning enough to leave for America, so she accepts a deal from an anti-Japanese independence group: spend 100 days undercover as an interpreter trainee at the Government-General of Korea, using the fake name Geum Seo-hee.

Inside the office she gets tangled up with Kim Tae-woong (Park Jin-young), a newly appointed interpreter who goes by the name Sato Hideo and is the adopted son of the Inspector-General, the second-highest-ranking official in the administration. The production team says the two meet by chance at Gyeongseong Station, and from there lies and suspicion drive the romance. One poster line sums it up: “Just once, tell me a real story that isn’t a lie.”

Who Is in the Cast?

Kim You-jung, known for Backstreet Rookie, My Demon and Dear X, plays Ga-kyeong. Park Jin-young, who led Our Unwritten Seoul and When My Love Blooms, plays Tae-woong. They are joined by Kim Hyun-joo, Lee Moo-saeng and Jin Seon-kyu, the other three leads confirmed by tvN. Jin Seon-kyu plays Sato Shinichi, according to Soompi’s preview coverage.

Behind the camera, director Yoo In-shik is best known for Extraordinary Attorney Woo and the Dr. Romantic series, and the script is by Ryu Bo-ri. That pairing alone makes it one to watch.

When and Where Can You Watch 100 Days of Deception?

The drama airs on tvN every Saturday and Sunday at 9:10 p.m. KST, starting October 10, 2026. It takes over the weekend slot that Four Hands, Two Sonatas held. Globally it streams on Netflix, with TVING carrying it in South Korea.

There are 16 episodes of about 70 minutes each, and the finale is currently listed for November 29, 2026, though release dates can change. In other words, you get two episodes a week for eight weeks.

Is It Worth Watching? What to Expect

Expect a mix of heist-style cons, spy tension and slow-burn romance, wrapped in a lavish recreation of 1932 Gyeongseong. tvN even aired a special, 100 Days of Deception: Secret Documents, on October 3, where the cast introduced their characters. If you liked period spy romances or enjoy a double-identity love story, this is an easy add to the watchlist.

FAQ

Is 100 Days of Deception based on a true story?

No source I found says it is based on a true event. It is an original script set in the real historical period of Japanese rule, with a fictional pickpocket-turned-spy as its heroine.

Is it the same as 100 Days of Lies?

Yes. The drama was earlier reported under the title 100 Days of Lies; the Korean title is 100일의 거짓말, and the English title is now 100 Days of Deception.

Is it on Netflix worldwide?

Netflix has listed it as streaming globally from the October 10 premiere, but regional availability can differ, so check your local Netflix library.

Whether you are here for Kim You-jung, Park Jin-young or the period spy plot, 100 Days of Deception looks like the big weekend K-drama of the fall. Check back for more K-drama guides and travel tips as the season unfolds.

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Read more about the series on 100 Days of Deception on Wikipedia.