Are you deciding whether to watch Netflix’s Mousetrap? This should help. Here’s why it’s worth your time and what to know going in. No spoilers.
Should You Watch Mousetrap? Watch It.
Short answer first: watch it.
Mousetrap wasn’t a massive pre-release event. Netflix put out a teaser and press materials in late July, but nothing about the run-up suggested what happened next. Within days of its August 28 premiere, it hit No. 1 on Netflix’s Korean series chart. By September 1, it was No. 6 globally on Netflix’s TV chart and in the Top 10 in 49 countries.
Decider praised how the unexpected teamwork between its leads and the pursuit of a mysterious rival keep viewers hooked. Other outlets pointed to how the show reframes an old folktale through the lens of modern technology and stolen identity.
Having watched it myself, I’ll add one thing reviews haven’t emphasized enough. The pacing is relentless. Most chase thrillers need three episodes to find their footing. This one gives you no room to breathe from episode one. The clues planted early pay off steadily as the season goes on, which is its own kind of satisfying.
The Folktale Where a Mouse Eats Your Fingernails and Becomes You
Korea has an old folktale about a mouse that eats a man’s fingernails and becomes him. A young nobleman throws his nail clippings around carelessly every night. A fieldmouse secretly eats them and transforms into his exact double. The fake takes over the young man’s house and identity, while the real one is thrown out and treated as the impostor.
The nobleman is eventually helped by an old monk, who hands him a cat and tells him to release it in front of the fake. Cats are the fieldmouse’s natural predator, and in front of one, the impostor can no longer hide what he is.
This story has circulated in Korea for a long time. Plenty of people grew up hearing some version of “don’t throw your nail clippings around, or a mouse will eat them and become you.” Mousetrap takes that old warning and drops it straight into a Seoul apartment, a bank, a courtroom.
One thing gets lost in translation, and it’s worth knowing before you watch. Netflix renders the folktale’s English title as “The Rat That Ate Fingernails,” and the show’s mysterious antagonist is called “the Rat.” Deuljwi literally refers more closely to a field mouse or wild mouse than the sewer-rat image the English word “rat” may suggest.
Why This Story Hits Differently in Korea
Korea’s relationship with personal identity is unlike most countries’. Decades of standoff with North Korea shaped a system where every citizen carries a unique resident registration number, and everyone registers their fingerprints with the state once they turn 17. In most countries, this would draw serious pushback. In Korea, it’s simply part of getting an ID card. On top of that, a government portal called Gov24 lets any citizen pull up official documents online, any time — a level of administrative digitization few countries can match.
In the past couple of years, the other side of that tightly-run system has been on full display. In 2025, a hack at SK Telecom exposed SIM card data for roughly 23 million users, and Korea’s data protection authority handed down a record fine of 134.8 billion won. That same November, roughly 33.7 million Coupang customer accounts had their personal information improperly exposed.
That’s the contradiction sitting underneath Mousetrap. A country where identity data is managed this tightly is also a country where it keeps leaking on this scale. The fear the show builds around losing your face, your fingerprints, your entire paper trail doesn’t feel like fiction to a Korean audience.
Sul Kyung-gu and Ryu Jun-yeol — Why This Pairing Matters
When these two names are attached to a project in Korea, acting quality stops being a question.
Sul Kyung-gu debuted in Peppermint Candy and went on to star in Silmido, the first Korean film to draw ten million theater admissions. He’s also known for The Merciless. Ryu Jun-yeol broke through with Reply 1988, held his own opposite Song Kang-ho in A Taxi Driver, and has kept building an eclectic filmography through projects like The 8 Show.
For Koreans, these two are more than well-known actors. They’re names you can recommend abroad without hesitation. This is the first time the two have worked together, and it’s also the first time Ryu has taken on a dual role. He’s spoken in interviews about using two different vocal registers to keep the two characters distinct.
A Webtoon That Already Had Its Own Readers
The source material, a webtoon called Field Mouse, was written by Ludovico and ran on Daum Webtoon (now Kakao Webtoon) from 2017 to 2020. It ran a full three years to completion and had a built-in readership well before this adaptation was ever announced.
The drama keeps the webtoon’s core setup and character dynamics but rewrites most of the plot from there. Whether or not you know the original, there’s something here for you. What exactly changed is a story for another post.
Who Should Watch This
- Anyone who likes identity-theft or doppelganger thrillers
- Anyone who wants to watch Sul Kyung-gu and Ryu Jun-yeol play off each other
- Anyone who wants a chase thriller with twists that never let up
- Anyone with time to binge it — this isn’t a show you can easily walk away from mid-season
Basic Info
- Creators: Kim Hong-sun (director), Lee Jae-gon (writer)
- Cast: Ryu Jun-yeol, Sul Kyung-gu, Lee Kyu-hyung
- Based on: the webtoon Field Mouse by Ludovico (serialized 2017–2020)
- Inspired by: the Korean folktale “The Fieldmouse That Ate Fingernails”
- Episodes: 10
- Release: August 28, 2026, globally on Netflix
Already finished all 10 episodes? Here’s the full spoiler breakdown, plus how the original webtoon differs.
Mousetrap: Full Story and Ending Explained
Mousetrap Ending Explained — The Clues You Missed and Who the Real Rat Was
Mousetrap Original Webtoon Explained — The Full Story and How It Differs From Netflix
Enjoyed the setup? Here are other Korean thrillers worth starting spoiler-free.
Should You Watch The East Palace? A Korean Viewer’s Take
Agent Kim Reactivated: What You Need to Know Before You Watch
A Shop for Killers Season 1: What You Need to Know Before Season 2
Did the fingerprint-and-ID-number system in this drama feel far-fetched to you, or oddly plausible? I’m curious how it reads to someone who didn’t grow up with it.
Some links in this post may be affiliate links. If you make a purchase through them, I may earn a small commission at no extra cost to you.