The Restless (2006 film)

The Restless is a 2006 South Korean fantasy film directed by Jo Dong-oh, starring Kim Tae-hee and Jung Woo-sung. The film's Korean title, "Joong-cheon", is literally translated as "Midheaven". Demon Empire is an alternative English name for the film.
Plot summary.
In fictional ancient Korea, Yi-gwak is a demon hunter who lost his lover, Yon-hwa, and colleagues of demon hunters in the past. He enters the Midheaven, a transitory place for spirits, only to find the spirit of Yon-hwa who has forgotten about him. His deceased former mentor, Ban-chu, masterminds a demonic rebellion in Midheaven, wishing to invade the living world.
Soundtrack.
"Memory of the Restless" OST.
The first soundtrack, "Memory of The Restless" OST, was released as an EP on Dec 14, 2006 by CJ Entertainment.
"The Restless OST".
A longer soundtrack, titled "The Restless OST", was released on Jan 19, 2007 by CJ Entertainment. It consists of the background music played throughout the film. All music was composed by Shirō Sagisu.