Big Mouth — Characters & Cast

Begins with a desire to clear his debts and protect his family; evolves into a mission to destroy Choi Do-ha's corrupt empire and avenge Mi-ho.

Transforms from a weak, talkative attorney with a 10% win rate into a hardened, highly calculating shadow leader who inherits the real Big Mouse organization.

Unshakeable faith in Chang-ho's innocence and an unyielding moral obligation to expose systemic injustice.

Evolves from a pragmatic nurse and supportive wife into a fearless field investigator who exposes NK Chemical’s environmental atrocities, sacrificing her own life for the truth.

Unquenchable thirst for political power, wealth, and executing historical revenge against Chairman Kang.

Introduced as a suave, reform-minded Mayor helping Chang-ho; unmasked as a cold-blooded killer who murdered Professor Seo, covered up toxic waste leaks, and manipulated high society for political dominance.

Maintaining his aristocratic standing, retrieving lost capital, and staying at the top of the NR Forum hierarchy.

Starts as the arrogant, hot-headed president of Gukdong Daily and leader of NR Forum, desperate to recover 100 billion won stolen by Big Mouse; shifts into a desperate figure caught between Chang-ho and Choi Do-ha.

Exposing the elite cover-up surrounding NF9 and the death of his daughter.

Introduced as an unassuming, quiet prison room leader skilled in reading tarot cards; revealed in Episode 12 to be the original Big Mouse seeking revenge for his daughter's death before passing his legacy to Chang-ho.