A taxi driver is found dead, and Hyun-woo, the only witness, charged with a murder and serves 10 years in prison. While offering pro bono services, a lawyer Junyoung meets Hyun-woo, and they begin their journey to prove his innocence.

Junho, a grade school student, is left all alone after his mom’s car accident. His half-brother’s father takes pity on him and brings him home. Knowing that he can be kicked out any day, Junho tries desperately to stay.

Ja-yoon is a high school student who struggles with memory loss after she endured some unknown trauma during her childhood. While trying to uncover the truth, she is unwittingly dragged into a world of crime and finds herself on a journey that will awaken many secrets hidden deep within.

Hong Gil-dong is an infallible private detective with an exceptional memory and quirky personality. While chasing the only target he failed to find, he gets entangled in a much bigger conspiracy than he bargained for.