A struggling lawyer gets pulled into a murder case and finds himself mistaken for a con artist in Big Mouth, a 2022 South Korean thriller series built around mistaken identity and the fallout of being labeled something he insists he is not.
What is Big Mouth about?
The series follows a small-time attorney whose career has gone nowhere, until a single case tangled up in a killing suddenly reshapes how everyone around him sees him. Once he is tagged as a swindler, the label follows him faster than he can argue his way out of it, and the people investigating the case begin treating the accusation as fact rather than a starting point. From there the show works as a slow unraveling: courtrooms, back rooms, and shifting allegiances all pull at a man trying to prove that the story being told about him is not the whole story. Mystery and legal drama trade off scene by scene, keeping the central question of who is really responsible open for most of the run.
About the cast
Lee Jong-suk leads as the lawyer at the center of the case, opposite Yoona, with Yang Kyung-won, Kim Joo-heon, Kwak Dong-yeon, Ok Ja-yeon, Lee Ki-young, and Oh Eui-shik rounding out the cast of investigators, colleagues, and rivals who shape how his story gets told. Director Oh Choong-hwan keeps the ensemble's performances grounded, which matters in a plot that leans heavily on how believable each character seems from one episode to the next.
Context & significance
Big Mouth runs roughly 60 minutes per episode and carries a strong 7.8 audience rating, reflecting the kind of word-of-mouth momentum South Korean thrillers have built internationally in recent years. It sits comfortably alongside other genre-blending Korean series that pair a legal or procedural frame with a bigger conspiracy underneath, and it holds its own combination of drama, mystery, and action rather than settling into a single lane.
Watching Big Mouth on Ktime
Big Mouth is available on K-Time with Persian subtitles, so the original Korean dialogue plays with Farsi text on screen throughout. A free K-Time account login is required to start watching, though this page and its details are open to read without one. K-Time's Farsi-language interface is designed for the Iranian diaspora, making series like this one easy to find alongside the platform's broader Korean and international catalog.