Euncheon

After his violent interrogation methods make headlines in the media, Detective Kwak Ho-jin is demoted to a rural backwater called Euncheon. From his very first day on the job, he receives a report that a dead body has been found in the reservoir. The person who first discovered the corpse is Jeong Ui-yeon, the village's hereditary shaman. As Ui-yeon falls under suspicion as the prime suspect, Ho-jin throws himself into the investigation, eager to crack the case and secure a quick transfer back to Seoul... But the more tangled he becomes with Ui-yeon, the stranger both the case and their relationship turn out to be. (Source: Lezhin, translated)

Original Webtoon:
Lezhin