Big Mouth Cast features a talented ensemble, led by Lee Jong-suk as Park Chang-ho, an average lawyer who unexpectedly gets entangled in a high-stakes conspiracy. Yoona stars as Go Mi-ho, Park Chang-ho’s devoted wife, who becomes crucial to uncovering the truth.
Table of Contents
Introduction

Big Mouth is a gripping South Korean legal thriller that delves into the dangerous world of corruption, conspiracy, and deception. The story centers on Park Chang-ho (played by Lee Jong-suk), a seemingly average, struggling lawyer who gets mistakenly identified as a notorious con artist known as “Big Mouth.” As he is forced into the high-stakes world of crime and corruption, Chang-ho’s life and that of his wife, Go Mi-ho (played by Yoona), are turned upside down. Together, they must navigate a treacherous web of lies, deceit, and powerful enemies to uncover the truth. Alongside them are key characters, including Choi Do-ha (played by Kim Joo-hun) and Joo Hyun (played by Yang Kyung-won), whose motivations and actions add layers of suspense and intrigue to the narrative.
Big Mouth Cast
Lee Jong-suk as Park Chang-ho
- Character Overview: Park Chang-ho is an underachieving, small-time lawyer with a knack for getting into trouble. His life takes an unexpected turn when he is mistakenly identified as the infamous criminal mastermind “Big Mouth.” As he is thrust into a world of conspiracy, corruption, and danger, Chang-ho must use his wits and legal knowledge to survive and clear his name. Despite his initial shortcomings, Chang-ho’s character grows significantly throughout the series, as he evolves from a helpless lawyer to someone who must confront dark forces and fight for justice. His loyalty to his wife and his determination to expose the truth make him a compelling and relatable character.
- Actor’s Background: Lee Jong-suk is a renowned South Korean actor who rose to fame with roles in hit dramas like Pinocchio, While You Were Sleeping, and W: Two Worlds. His ability to portray a range of characters with emotional depth and complexity shines in Big Mouth, making his performance a standout in the series.
Yoona as Go Mi-ho
- Character Overview: Go Mi-ho is Park Chang-ho’s intelligent and fiercely devoted wife. A former nurse, Mi-ho is determined to support her husband through his struggles, even when his life spirals out of control after he’s implicated in the “Big Mouth” scandal. Mi-ho plays a pivotal role in the story, as she helps Chang-ho uncover the truth behind the conspiracy while also dealing with her own personal challenges. Her character is strong, resourceful, and emotionally complex, making her an essential part of the series. As the story unfolds, Mi-ho’s involvement in the dangerous situation becomes more critical, highlighting her resilience and determination.
- Actor’s Background: Yoona, a member of the K-pop group Girls’ Generation, has established herself as a successful actress with roles in dramas like The K2, Hush, and Love Rain. Known for her graceful presence and versatility, Yoona brings depth and sincerity to the role of Go Mi-ho, making her a standout in Big Mouth.
Kim Joo-hun as Choi Do-ha
- Character Overview: Choi Do-ha is a powerful and influential figure who plays a crucial role in the series. As a person of authority, he is deeply involved in the corrupt world that Park Chang-ho and Go Mi-ho find themselves entangled in. Choi Do-ha’s actions and motivations add a layer of mystery and danger to the series, as his true intentions are often ambiguous. He serves as one of the primary antagonists, manipulating situations to his advantage while also being a key player in the larger conspiracy.
- Actor’s Background: Kim Joo-hun is a seasoned actor known for his roles in dramas like My Beautiful Bride and Miss Lee. His portrayal of Choi Do-ha showcases his ability to embody morally complex characters, adding an intriguing layer of depth to the series.
Yang Kyung-won as Joo Hyun
- Character Overview: Joo Hyun is a cunning and ambitious character whose actions often serve to advance the corrupt agenda that surrounds Park Chang-ho. As a figure with hidden motivations, Joo Hyun’s involvement in the plot adds layers of suspense, as viewers are left questioning his true loyalties. His interactions with Chang-ho and other key characters create a sense of unease, as he proves to be a pivotal player in the unfolding mystery.
- Actor’s Background: Yang Kyung-won is known for his work in dramas such as Stranger and Voice. His portrayal of Joo Hyun adds a sense of intrigue and unpredictability to Big Mouth, making him an essential part of the cast’s dynamic.
Supporting Cast
. Ok Ja-yeon as Miho’s Mother (Go Mi-ja)
- Character Overview: Go Mi-ja, played by Ok Ja-yeon, is Go Mi-ho’s (Yoona’s) mother, who brings emotional depth to the family dynamic. Mi-ja’s relationship with her daughter is often strained, yet it is clear that she cares deeply for her family. Her character adds a layer of family conflict and complexity, particularly in moments when Mi-ho must balance her devotion to her husband and the difficult family relationships she navigates. Mi-ja’s decisions and actions, while secondary to the main plot, contribute to the emotional stakes of the story.
- Actor’s Background: Ok Ja-yeon is a talented actress known for her roles in Vagabond and The Queen of Office. Her ability to portray complex maternal figures adds an additional layer of emotional tension in Big Mouth.
2. Kim Kwang-kyu as Park Chang-ho’s Father
- Character Overview: Park Chang-ho’s father plays a significant, albeit more minor, role in the series. His relationship with Chang-ho adds to the backstory of the character, helping to shape the moral and emotional journey of the protagonist. As the show progresses, the father-son dynamic contributes to Chang-ho’s inner conflict and development, as well as his motivations to uncover the truth about the conspiracy he’s involved in.
- Actor’s Background: Kim Kwang-kyu is known for his long career in both television and film, often portraying characters that have a grounded and familial connection to the leads. His experience brings authenticity to his role in Big Mouth.
3. Lee Ki-young as Jang Hyeon
- Character Overview: Jang Hyeon, portrayed by Lee Ki-young, is an intriguing character who works in the legal and criminal world. While his role is more secondary compared to the main players, his presence is critical in shaping the moral dilemmas that the protagonists face. Jang’s loyalty and motivations are often questioned, adding suspense to the drama. As the plot unfolds, his character is involved in a web of corruption, forcing the main characters to confront not only their own moral compasses but also the larger system of deceit that surrounds them.
- Actor’s Background: Lee Ki-young is a veteran actor who has appeared in numerous K-dramas such as The King: Eternal Monarch and The Night Watchman’s Journal. His experience in portraying morally ambiguous characters makes him a perfect fit for Big Mouth.
4. Kwon Hwa-woon as Kim Gyeong-sun
- Character Overview: Kim Gyeong-sun, played by Kwon Hwa-woon, is a supporting character whose role impacts the tension within the plot. As someone connected to the larger conspiracy, Kim’s actions and decisions create turning points in the story. Her character’s interactions with the main cast serve to deepen the mystery, providing clues and obstacles that Chang-ho and Mi-ho must navigate as they uncover the truth.
- Actor’s Background: Kwon Hwa-woon is an emerging actress known for her roles in dramas like The Uncanny Counter and Cheat on Me, If You Can. Her portrayal of Kim Gyeong-sun is subtle yet impactful, adding to the complex web of intrigue in Big Mouth.
5. Ahn Nae-sang as Choi Do-ha’s Ally
- Character Overview: Ahn Nae-sang plays an important supporting role as Choi Do-ha’s ally, whose influence within the story brings additional layers of tension and danger. As an accomplice in the web of corruption, this character’s decisions have significant consequences for the lead characters, particularly for Park Chang-ho, who is increasingly caught up in the conspiracy. The moral ambiguity of this character adds an unpredictable element to the storyline.
- Actor’s Background: Ahn Nae-sang is a well-established actor known for his performances in My Country: The New Age and The Penthouse. His ability to portray morally complex characters makes him a key supporting presence in Big Mouth.
6. Joo Hyun as Kim Seong-jae
- Character Overview: Kim Seong-jae, portrayed by Joo Hyun, is another secondary character whose actions provide crucial information to the lead characters. His involvement in the unfolding events adds to the sense of urgency and tension, particularly as his knowledge of the corrupt system becomes a valuable resource for Park Chang-ho and Go Mi-ho.
- Actor’s Background: Joo Hyun has made appearances in dramas like Stranger and Chicago Typewriter, known for his ability to portray characters that play important yet understated roles. His role in Big Mouth complements the high stakes of the main plot while adding an element of intrigue.
Conclusion
In conclusion, Big Mouth is a captivating legal thriller that blends suspense, conspiracy, and emotional depth through its talented cast. The main characters, particularly Lee Jong-suk as Park Chang-ho and Yoona as Go Mi-ho, anchor the series with compelling performances, portraying an average lawyer and his strong-willed wife caught in a dangerous game of deception and corruption. Their chemistry and emotional journey are central to the story’s progression, as they navigate a treacherous world filled with dark secrets and high-stakes challenges.
Friendly Rivalry Cast & Their Role (2025) Thriller Drama
(FAQs)
Who plays Park Chang-ho in Big Mouth?
Lee Jong-suk plays Park Chang-ho, the main protagonist. He is a struggling lawyer who becomes entangled in a dangerous conspiracy after being mistaken for the notorious criminal mastermind “Big Mouth.”
Who is Go Mi-ho, and who plays her?
Go Mi-ho, portrayed by Yoona, is Park Chang-ho’s devoted wife. She plays a crucial role in the series as she helps her husband navigate the conspiracy while balancing her personal and professional struggles.
What role does Kim Joo-hun play in Big Mouth?
Kim Joo-hun portrays Choi Do-ha, a powerful and influential figure involved in the corruption surrounding Park Chang-ho. His character adds complexity and moral ambiguity to the storyline.
Who is Joo Hyun, and who plays him?
Joo Hyun, played by Yang Kyung-won, is a cunning and ambitious character whose actions contribute to the conspiracy. His character adds suspense and unpredictability as he becomes more involved in the main plot.
Is Lee Jong-suk’s character in Big Mouth different from his previous roles?
Yes, Park Chang-ho is a departure from Lee Jong-suk’s previous roles. While he has portrayed many strong and heroic characters, Chang-ho is an ordinary man forced into extraordinary circumstances, showcasing Lee Jong-suk’s range as an actor.
What is Yoona known for aside from Big Mouth?
Yoona, a member of Girls’ Generation, has built a successful acting career with roles in dramas like The K2, Hush, and Love Rain. Her portrayal of Go Mi-ho in Big Mouth highlights her ability to portray a strong, supportive character caught in a web of conspiracy.
Who plays Go Mi-ho’s mother in Big Mouth?
Ok Ja-yeon plays Go Mi-ho’s mother, Go Mi-ja, a character who adds emotional depth to the series, particularly in her interactions with her daughter and the challenges they face as a family.
What is the significance of Choi Do-ha’s character?
Choi Do-ha, played by Kim Joo-hun, is one of the main antagonists. His character’s involvement in the conspiracy around “Big Mouth” creates significant tension throughout the series, as his moral ambiguity and power make him a dangerous figure for Park Chang-ho and his family.
Does Yang Kyung-won have other notable roles?
Yes, Yang Kyung-won has appeared in notable dramas such as Stranger and Voice. In Big Mouth, his portrayal of Joo Hyun adds a layer of unpredictability and intrigue, further solidifying his reputation for playing morally complex characters.
What role does Ahn Nae-sang play in Big Mouth?
Ahn Nae-sang portrays an ally of Choi Do-ha, a character whose involvement in the conspiracy makes the story even more intricate and suspenseful. His role adds a layer of danger and intrigue as the characters face off against powerful figures.
Is there a strong focus on the family dynamic in Big Mouth?
Yes, the family dynamic, especially between Park Chang-ho and Go Mi-ho, plays a central role in the series. Their relationship is tested throughout the show as they face immense challenges, with Go Mi-ho’s unwavering support being crucial in Chang-ho’s journey to uncover the truth.
Does Lee Jong-suk’s character evolve throughout the series?
Yes, Park Chang-ho undergoes significant character development. He transforms from a struggling lawyer into a man who must navigate the world of corruption and deception. His growth and the choices he makes become central to the series’ narrative.