Titled “Foolish Heart,” the soundtrack became the most searched term online in Korea upon its sneak pre-release during an episode of ‘Heaven’s Will’ last week.
Themed around the tear-jerking love story between Lee Dong Wook and Song Ji Hyo, the song contains everything from the subtleties of romance to the fragility of the human heart.
“Foolish Heart” was composed by Wi Jong Soo and written by Kang Woo Kyung.
The production company of the OST stated, “JYJ Junsu poured his heart out for the recording of this song and participated in the mixing work near the end of the song. He showed a lot of dedication and passion for this work. All the staff members were very impressed by what he did.”
This is JYJ Junsu’s third time working on an Original Soundtrack for a KBS drama. His previous works were in ‘Sungkyunkwan Scandal’ and ‘The Innocent Man’ both of which were successful.
“Foolish Heart” officially released at noon on May 15 in Korea.
JYJ3 
Great pic of Junsu
Today is May 15, any news on how to buy this song for iFans?
I’ll be looking to purchase this song!
junchan ❤ this song is very interesting! the best singer!
seriously proud of this guy!
this song is really good… i fallen in love with this song…
wow…..thanks for such awesome OST, i really love it…
I love this song!!! Junsu’s soulful voice is perfect for it! 😀
I’m glad that Junsu lends his voice for Mandate of heaven..heard, some fans now starting to watch this drama after knowing that junsu has sing an OST in this..wow, really it’s junsu effect..