tvN’s 100 Days of Deception has become one of the most talked-about weekend dramas in South Korea. Ratings for the period spy romance climbed from 5.3 percent in its first episode to 7.6 percent in its second, according to Nielsen Korea. The jump came as Kim Yoo-jung’s character, Lee Ga-kyung, stopped running from trouble and started working as an undercover spy. The drama still trails Kim Ji-won’s Doctor X in the same Saturday night window, but its upward move has given tvN a strong performer in its 20th-anniversary year.
Ratings Jump From 5.3 to 7.6 Percent
100 Days of Deception premiered on October 10, 2026, with an average nationwide rating of 5.3 percent. That made it the most-watched cable show of any kind on that Saturday and the highest premiere rating of any tvN Saturday-Sunday drama in 2026.
The second episode, which aired on October 11, rose to 7.6 percent nationwide. It peaked at 8.5 percent. In the Seoul metropolitan area, the episode averaged 8.3 percent and peaked at 9.4 percent. The drama took first place in its time slot across all cable channels for that night.
Episode three, which aired on October 17, came in at 7.0 percent nationwide. The number was slightly lower than the second episode, but the drama still held its place as the most-watched cable show on Saturday. Nielsen Korea data shows the series has stayed above 7 percent since its second episode, a solid range for a tvN weekend drama.
Kim Yoo-jung Steps Into the Spy Role
The ratings rise follows a major story turn. Lee Ga-kyung begins the series as a skilled pickpocket in 1932 Gyeongseong. Her main goal is to save enough money to leave Korea and start a new life in America. She is not a patriot at first, and the drama does not pretend otherwise. Her survival comes before any larger cause.
That changes after she takes a deal with Yoo So-ran, played by Kim Hyun-joo, the leader of an independence group. Yoo So-ran offers Lee Ga-kyung a way out: work as a spy inside the Japanese Government-General of Korea for 100 days, and she will help her get to America. Lee Ga-kyung accepts and goes undercover as an interpreter trainee named Geum Seo-hee.
Kim Yoo-jung spoke about the character at the drama’s press conference. She said the role’s growth was a key reason she took the part.
“Ga-kyung is in her early 20s — a vulnerable age when she hasn’t even figured out what her dreams are. I was fascinated to see how a young person living through that era would evolve.”
The actress also said the script and the people behind the project drew her in.
“I chose this drama because of the director, writer and cast. Reading the script made me feel that just being part of this project would be a privilege in my acting career, and I truly wanted to do it.”
Park Jin-young and the Cast Around Her
Park Jin-young of GOT7 plays Kim Tae-woong, also known as Sato Hideo. He is an elite interpreter at the Government-General and the adopted son of Sato Shinichi, played by Jin Seon-kyu. Sato Shinichi is the Inspector-General of Korea, the second-highest-ranking official in the colonial administration.
Kim Tae-woong and Lee Ga-kyung keep meeting in dangerous places. Their relationship grows while both hide their real identities. The romance adds tension to the spy mission, and the drama uses their scenes together to show how trust works in a place where almost everyone is lying.
Kim Hyun-joo plays Yoo So-ran, the independence group leader who recruits Lee Ga-kyung. Lee Moo-saeng plays Yoo Phillip, a group member who doubts the new spy’s loyalty. Kam Woo-sung appears as Geum Seok-joong, a figure tied to the assassination plot against Sato Shinichi.
The series is directed by Yoo In-shik, known for Extraordinary Attorney Woo and Dr. Romantic. Ryu Bo-ri, who wrote Do You Like Brahms?, wrote the script. The production is a special project for tvN’s 20th anniversary.
Doctor X Still Leads the Saturday Night Race
Kim Ji-won’s Doctor X remains the bigger ratings performer in the same Saturday window. The SBS medical noir premiered on October 9 with 11.4 percent nationwide. It rose to 14.9 percent in episode two, 15.1 percent in episode three, and 18.5 percent in episode four, its highest number yet.
The gap between the two dramas is wide. Doctor X is drawing more than double the audience of 100 Days of Deception on the same night. The comparison matters because both shows air on Saturdays and both target the same weekend drama audience.
100 Days of Deception does have one advantage: it airs on cable through tvN, while Doctor X airs on free-to-air SBS. Cable ratings are usually lower than free-to-air numbers, so the two figures are not a direct like-for-like measure. Even with that difference, Doctor X is clearly ahead in raw viewership.
Buzz Rankings Put the Drama Near the Top
100 Days of Deception ranked No. 3 on Good Data Corporation’s weekly list of the most buzzworthy dramas. Kim Yoo-jung ranked No. 3 on the actor list, and Park Jin-young ranked No. 9. Doctor X and Kim Ji-won took the top spots on both lists.
The buzz ranking measures news coverage, blog posts, online communities, videos and social media activity. A No. 3 finish puts 100 Days of Deception in the conversation alongside the season’s biggest shows, even if its ratings are lower than Doctor X.
Related Stories
View all articles about
Where to Watch and When New Episodes Arrive
100 Days of Deception airs on tvN in South Korea every Saturday and Sunday at 9:10 p.m. KST. Netflix streams the series globally, including in the United States, United Kingdom, Canada, Australia, India and other markets. New episodes arrive on Netflix alongside the Korean broadcast, with exact drop times depending on the region.
The series has 16 episodes. Episode four aired on October 18. Episode five is scheduled for October 24 at 9:10 p.m. KST. The finale is set for November 29.
Also Read: 100 Days of Deception Episode 2 Recap: Ga-gyeong Caught Between a Pawnshop and a Lie as Ratings Rise
For more K-drama ratings breakdowns and cast updates, keep VvipTimes bookmarked.
Leave a Reply