"The Morose Mononokean" is a Japanese manga series written and illustrated by Kono Kato. It follows the story of Hanae Ashiya, a high school student who becomes possessed by a yōkai, a spirit or supernatural being. To rid himself of this spirit, he seeks help from Akeno Hyouma, a mysterious and somewhat grumpy man who works as a guide for lost souls. The series blends elements of fantasy and supernatural themes, exploring the interactions between the living and the dead. As Hanae learns more about the world of mononoke and the spirits that inhabit it, he develops a deeper understanding of life, death, and the importance of helping others.