Actress Han Hyo Joo has personally written a letter that will be included in As One's Love Tonic album. Love Tonic is a mutoessay (music + photo + essay) which features songs, a picture spread of Han Hyo Joo, and an essay written by author Kim Hyun Hee all of which are about love. The title song on the album is "Leave" (or Love Tonic) and the music video features Han Hyo Joo.
PB Entertainment revealed that there will be 400 limited edition Love Tonic albums signed directly by Han Hyo Joo, but only one will contain Han Hyo Joo's letter. Han Hyo Joo revealed pictures on her cyworld of her working on the letter and expressed her excitement "As I sign each album one by one with love and care, I get excited thinking about whose hands these albums will fall into. Who will receive it?"
You can watch Han Hyo Joo in As One's Love Tonic here: