Xiah Junsu and Zhang Li Yin - Timeless MV. in this video features Hankyung and Siwon.

The brief story about the MV: Hankyung and Lee Yeonhee were a couple. Siwon was the bad guy. one day he held Lee Yeonhee as a hostage while he was being chased by the police. Hankyung was the police officer who was ordered to catch Siwon. Hankyung found the hostage was his girlfriend and got enraged. Siwon shot Hankyung at his head and Hankyung went to coma. And he was believed unable to wake up so the family decided to give up and donate his organs to other people. Siwon escaped eventually but Siwon got a heart condition and need a transplant. Now you know where Hankyung's heart went. After the transplant, Siwon felt his heart hurts whenever his saw lee yeonhee and then he found out that the heart beating inside his body now belonged to somebody he killed and the guy was the girl's loved one.