The Ghost Detective in the Tobacco Smoke

Vengeful spirits, or ghosts, are nonhuman beings formed when a person's resentment lingers after death. Those who deal with them are called ghost hunters. There are different schools of ghost hunters, each with its own abilities, all of which come from resentment. The resentment doesn't come from the hunter, though, but from the ghosts. Places where ghosts gather are called ghost zones. The protagonists, Ding Jiuhan and his younger sister Ding Xi, are two ghost detectives, or, more specifically, ghost hunters who investigate ghost zones.