Tiger JK released his new single, "I Know" at 12 PM KST of July 2.

On June 1, Tiger JK's agency, Feel Ghood Music, released a teaser video on YouTube. Many fans who saw the video were moved by Tiger JK's acting skills and expressed awe at the track's artistic value.

"I Know" is the second track from his Love Letter for Fans Project. The first track, "Forever," was released on June 16. Through "Forever," he sent his messages of love to his fans who have grown old with him. In "I Know," he sends messages of empathy to those who feel exhausted from life.

"We live in a world where those who wish to live an honest life are called idiots. Expediency and selfishness rule the world and everyone is always so busy sprinting toward what society sees as success. This is not an easy world for nice people," Tiger JK explained.

"No one listens when they want to plead about their grievous situations. That's reality, and I sang about it," he added.

Just like his previous "Forever" music video, Tiger JK completely self-produced the music video of "I Know." It was also revealed that Tiger JK left hints for the next track's theme in the music video.

Tiger JK will later produce cassette tapes of his tracks and evoke nostalgia among his fans.