"One Ordinary Day" is a criminal drama about a young man named Hyun Soo, who's wrongfully arrested and accused of the murder of a girl he met the night before.
The story is about everything he's being through, all the process with the arrest, the trial, living in prison with other inmates and trying to survive in there.

Kim So Hyun's acting is really good. I loved the way he was able to express Hyun Soo's feelings about being accused of something he didn't do, you could see in his eyes. Even his naive way of trusting the police, who was trying to pin the murder on him.
I never thought Hyun Soo was guilt, the police only had circumstantial evidence, but they still went along with that and did everything to make Hyun Soo the culprit, even tampering with evidence. That's the funny thing, even in the end, when Joong Han discover the truth and finds the real killer, the prosecutor and the police still ends up the good guys, saying they continued the investigation... which we know it's a lie. They wanted to end the investigation and chose Hyun Soo to be the fall guy, not caring if he was really the killer or not, they just needed someone to blame.

Cha Seung Won's character is very interesting, but his characterization was bad, he looked twice his age. HAHAHAHA'
I know his role was that of a low-class lawyer, but even so, they didn't need to make him like that.

The drama also shows how the justice system is flaw and broken. The judge convicted Hyun Soo to life imprisonment and he was innocent. Even with Joong Han showing everything the police did, how they made him the prime suspect without any convincing evidence, how they never looked into anyone else, even the people in Guk Hwa's life and still, he was found guilty. It's really awful to think that someone could be rooting in prison for something he didn't do.