One ordinary day is based on the firstseason of British drama Criminal Justice. It is about Kim Hyun Soo, a young man who is accused of murder after a drunken and drug-filled night out, though is unable to remember committing the crime.

While singal has more elemnts of sci-fi (like a walkie-talkie that connect two timelines), both dramas masterfully deal with police investigations, and political corruptions that try hiding the truth.