Kim Jaehwan released two music video teasers - a prologue film, and an epilogue film for the title song 'I Thought I Forgot Everything' from his fourth mini-album 'THE LETTER', which was released at 6 pm of December 26th and 27th.

In the music video teaser video, Kim Jae-hwan looks sentimental while looking at the camera and doing pottery, like the main character in the movie. In the second teaser video, Kim Jaehwan's sobbing acting was unfolded, making the viewers' hearts ache.

The prologue film and the epilogue film have attracted attention since their release because of their different teaser contents. Kim Jaehwan's work professionalism raises expectations for the album's perfection.

'I Thought I Forgot Everything' is a genuine ballad song about a man who realizes too late the importance of his lover after the breakup and regrets it. Kim Jaehwan's appealing vocals and delicate emotional expression will be further upgraded.