Oni is an ongoing, bimonthly series of graphic novels (considered by some to be modern Märchen), written and illustrated by Bob Teaman. It first began publication in LY 895. The story contains many references to mythical creatures of a region on Earth called Nihon, though it is set on The Land. The time in which it is set is never specified, though it seems to be a fictionalized version of the Land, which may contain anachronisms, as well as creatures or things which have never existed on the Land, in reality. It is, however, believed by many fans to be set sometime in the latter half of the sixth century. (While actual Landian villages may occasionally be named, the story is set in a version of the Land which has many more villages than the Land does even now.) In the world of Oni, some mythical creatures are real (including those that actually exist on the Land and those that don't), though many of the characters known by the names of such species are actually just people in costumes. The protagonist himself is called Oni, which is a a mythical creature from Nihon, though it is never revealed whether he is an actual oni, or merely wearing a costume.
Oni is a conflicted hero, who travels the land having various adventures. In spite of usually performing random acts of heroism, he can often do things which are seen as villainous, and even occasionally teams up with enemies who are more clearly villains, when they have common goals. He is a dark and tormented soul, and little is known of his past, though it is generally believed he wishes to atone for some past wrongdoing (which is presumably far worse than any of his wrongdoings in the present). For the most part, he travels alone, and while some of those he has helped in the course of his journeys would like to consider him a friend, he demonstrates little if any desire to actually cultivate friendships or lasting relationships of any kind.
While most of his adventures are self-contained stories, and most characters he meets are never seen again, there are several recurring characters. Most notable among these is a villain called Tengu (another creature from Nihon's folklore); like Oni, it is unclear whether Tengu is actually a creature or if that is just the name he goes by. There is also a widespread, evil organization called "Death's Head," whose membership includes both humans and various mythical creatures. This organization controls the local governments of many villages, and causes suffering for many people. The organization considers both Oni and Tengu to be outlaws, and while the two of them are most commonly enemies, it is their mutual opposition to Death's Head that most often leads to their occasional team-ups. The leader of Death's Head is named Enma (after a death deity, though the character is known to be human). The title he claims for himself is shogun, though he ultimately hopes to take control of every village and declare himself emperor, which is something Oni has sworn he will never allow to happen.