Park Changho is known since his school days as "Big Mouth" because he talks big and promises big things but cannot follow it up. He is also an infamous lawyer with a very low rate of success who was hired by a mayor because of his incompetence. Unfortunately, he was framed as the notorious and mysterious swindler "Big Mouse" and sent to prison. Go Miho is Changho's loving wife who works as a nurse. She has strong personality and will do anything to prove the innocence of her husband and help solve the case the mayor has given to her husband. Will Miho be successful in proving her husband's innocence? Or will her investigations lead to opening a can of worms?

• Lee Jong-suk
• Yoona
• Kim Ju-hun
• Kwak Dong-yeon
• Yang Kyung-won
• Ok Ja-yeon
• Oh Eui-sik
• Kim Jeong-hyeon