100 Days of Deception Opens at 5.3% With Kim You-jung

5.3%. That’s where Kim You-jung and Park Jinyoung’s spy romance opened, and honestly, a premise this good deserved a strong start. 100 Days of Deception debuted on October 10 with the highest first-episode rating of any tvN Saturday–Sunday drama in 2026, according to Soompi’s report citing Nielsen Korea.

Kim plays opposite GOT7’s Park Jinyoung, and the series is streaming on Netflix. The hook is one I’d click on from the logline alone: a pickpocket trying to escape colonial Korea ends up stealing government secrets, and a romance unfolds inside the institution she has infiltrated.

100 Days of Deception leads tvN’s 2026 weekend premieres

The 5.3% is an average nationwide household rating, and MoneyToday specifies Nielsen’s paid-platform household measurement. It also has the two numbers that give it context: Filing for Love opened at 4.4% and Undercover Miss Hong at 3.5%.

Do the subtraction and the new drama leads by 0.9 percentage points over Filing for Love and 1.8 points over Undercover Miss Hong. Same channel, same Saturday–Sunday category, same year, first episodes only: that is as clean as a ratings comparison gets, and nearly a full point at this level is no rounding error. The harder part is getting viewers back, which is why my forecast below sits on episode 4.

A pickpocket, an interpreter and an assassination mission

The story is set in 1932 Gyeongseong under Japanese colonial rule. In Yonhap’s premiere report, Kim’s Lee Ga-gyeong dreams of reaching America until a stolen bag pulls her into an assassination operation. This is the smartest thing in the premise: she has an escape plan before she has a cause. A heroine who wants out rather than in gives the resistance story a personal starting point, and every step deeper into the mission should cost her the exit she actually wanted.

Soompi’s script-reading preview has Ga-gyeong infiltrating the Japanese Government-General as an interpreter trainee. Park plays elite interpreter Kim Tae-woong, also known as Sato Hideo, the adopted son of Inspector-General Sato Shinichi, played by Jin Sun-kyu. Netflix’s synopsis makes the problem plain: her love interest is her target’s son, and he already holds the kind of post she is only pretending to train for. The conflict is built into the job titles, which is how I like my spy romances.

The supporting pair is lying too. Kim Hyun-joo plays resistance sniper Yoo So-ran, and Lee Moo-saeng is Yoo Philip, a correspondent for an American news agency who also works with the resistance. The two keep up a fake marriage. A drama about false identities that hands its second pair a fake marriage knows exactly what it is about.

Both leads arrive from modern romance. Kim’s My Demon (2023, opposite Song Kang) paired a powerless demon with an heiress, and Park’s Our Unwritten Seoul (2025, opposite Park Bo-young) was built on twin sisters swapping identities, as Netflix’s listing and announcement show. Going from a swapped-identity story to a character with two names is a nice echo for Park. Trading contemporary love stories for period espionage is the right risk for both of them.

Soompi’s script-reading report names Ryu Bo-ri as writer and Yoo In-shik as director, and Netflix’s official listing credits both alongside Kim Yoon-jin among its creators. Yoo’s earlier series include Extraordinary Attorney Woo and Dr. Romantic, per the same report, and that résumé is why I am taking this seriously. If the two names attached to Park’s character trip you up, our drama page keeps the principal cast in one place.

The city is divided, too. A tvN exhibition guide using Seoul Museum of History material explains that Namchon, south of Cheonggyecheon, became associated with Japanese residents, while Bukchon to the north was where Koreans lived. Japanese institutions began concentrating in the south in the late 1890s; from the mid-1920s, colonial governing facilities and upscale residences spread north too. The guide says the drama reflects that Korean-north, Japanese-south division. For a story about a woman walking into the colonial government’s offices under false pretenses, a city already split between Korean and Japanese sides is a gift.

The 100 days in the title are the length of the mission, not an episode count. Netflix files the series under political drama and period romance, and my money is on the second label doing the heavy lifting.

Early viewers praise the pace, with reservations

Early enthusiasm is easy to find in one Reddit premiere discussion. The original poster praises the acting, costumes and cinematography, compares the period setting with Mr. Sunshine and calls this opening faster paced. A Mr. Sunshine comparison after one episode is a big swing, and I admire the nerve. Another commenter likes the performances and the action but calls out some outdoor CGI.

Not everyone is sold. Some in the same thread would rather wait for the full run because strong starts have burned them before, and one worries about a bittersweet ending. I am with the waiters on principle and with the worrier on instinct: a love story with her target’s son in 1932 Gyeongseong does not obviously end at a wedding.

Where to watch and when the next episodes arrive

Netflix put the series in its official October 10 release lineup, and the active title page lists the first episode at 74 minutes, so this is not a lunch-break opener. Check the title in your own Netflix account for regional availability; our licensed K-drama streaming guide explains how to find the local service.

tvN’s official schedule lists episode 2 for October 11 at 9:10 p.m. KST on Korean television; Netflix viewers will find their local time on the episode listing.

What’s on Netflix’s advance schedule lists 16 episodes released on Saturdays and Sundays, with a planned November 29 finale, and the outlet itself flags that dates may change. Two a weekend makes eight weekends, plenty of runway for a 100-day countdown.

On that timetable, episodes 3 and 4 land on October 17–18, with another pair each weekend through November. If you are with the waiters from that Reddit thread, the full season is a late-November binge. Our K-drama episode-count guide explains the 16-episode format, and the November drama guide covers the month the finale is due.

Mina’s Take

What I want from the next episodes is simple: keep Ga-gyeong’s own ambitions visible once the resistance mission takes over her life. A pickpocket who wants a different life has something specific to lose, and if her reasons for each risk stay clear, the espionage can be as compelling as the attraction to an interpreter tied to the colonial administration. The ratings case is easier. A 5.3% opening that already tops this year’s tvN weekend premieres has room to climb once word of mouth spreads. My call: the opening grows to more than 6.0% nationwide by episode 4, scheduled for October 18 under the weekend plan. If that episode finishes at 6.0% or below, I got it wrong.

What to watch next

• October 11: episode 2’s tvN broadcast, followed by its Nielsen nationwide rating.
• October 17–18: the next scheduled weekend pair and episode 4’s result against Mina’s 6.0% forecast.
• November 29: the planned finale.