To Not Be Eaten By The Demon

Struggling writer Suoh Kuraha stumbles across a house-sitting job at an old Japanese house in the middle of nowhere where he's told never to open the door to a room in the back. One day, as thunder and lightning strike outside, Suoh hears a sound coming from the room and opens the door to check if everything is okay. Sitting behind wooden bars is a demon demanding to eat his spirit.

(Source: Renta!)