Nobody Knows director shared the meaning behind the drama's title. Some little things are significant in the series, and the title of it doesn't differ. The viewers even wonder more if the title also suggests something more, or is it connected to the movie of the same title that touches on the subject of child abuse.

Having only four episodes left until the end of the drama, director Lee Jung Heum revealed the secrets behind the show's title.

• Relation to the topic of the drama

Lee Jung Heum expressed that the first one is connected to the drama's topic. He went on, "Will the truth be revealed and the problem solved if the culprit is caught? I don't think it's easy to find out the truth behind a crime. The truth that is hidden by the culprit and lied about becomes a truth that 'nobody knows.' But if you try to listen to the perspectives of the victims and the people around the victim, 'anyone can know' because victims don't lie."

Lee Jung Heum added, "Cha Young Jin (played by Kim Seo Hyung) is not a character that acts out of personal ambitions of getting revenge on the culprit. She's a character that chases the culprit because she wants to learn why her friend was killed instead of her and because she wants to remember her friend's final moments through that truth. She holds onto this case for 19 years because she wants to properly listen to and remember the final story of her friend and victim Soo Jung. This becomes her motivation for listening to the stories of marginalized children such as Eun Ho (played by Ahn Ji Ho), Dong Myung (played by Yoon Chan Young), and Min Sung (played by Yoon Jae Yong). In that sense, the title 'Nobody Knows' paradoxically signifies how Cha Young Jin listens to the stories that 'nobody knows' and comforts the children."

• Relation to the hidden secret

The director said that the second aspect is connected to the drama's hidden secret. It is connected to the bible verse Matthew 24:36, which is: "But about that day or hour no one knows, not even the angels in heaven, nor the Son, but only the Father.' This is very much linked to the secret of the major piece of evidence 'Testament to New Life,' which will soon be unveiled in the drama."

• Relation to the film of the same title

Lastly, Director Lee Jung Heum said that the third aspect is linked to the film Nobody Knows, helmed by Hirokazu Koreeda. The series is somehow connected to this film that was based on the actual events of children from the marginalized community.