In the Edo period, there was a shrine maiden called "Itsukihime" in the mountain village of Kadono. Jinta, a young man who acts as the shrine maiden's guardian despite being a stranger, encounters a mysterious demon who speaks of the far future in the forest where he went to defeat it. From Edo to the Heisei era, this huge Japanese fantasy series follows a demon man who travels through time while continuously questioning the meaning of wielding a sword.

Allen, a misanthropic wizard, lives deep within the forest. He is known as the "Demon Lord" and feared by those around him. One day, while living his life as a hermit, he comes across a young girl named Charlotte who has collapsed in the forest. Despite being innocent, she was accused of evil deeds, had her engagement annulled, and was forced to flee her country. When he heard that, Allen remembered the agony of being betrayed by a group he once thought was his companions. After hearing the story of the 17-year-old's exploitation, Allen decides, "I'll let her live in my mansion, and I'll teach her all sorts of bad things..."

Twenty-two-year-old Eikichi Onizuka—ex-biker gang leader, conqueror of Shonan, and virgin—has a dream: to become the greatest high school teacher in all of Japan. This isn't because of a passion for teaching, but because he wants a loving teenage wife when he's old and gray. Still, for a perverted, greedy, and lazy delinquent, there is more to Onizuka than meets the eye. So when he lands a job as the homeroom teacher of the Class 3-4 at the prestigious Holy Forest Academy—despite suplexing the Vice Principal—all of his talents are put to the test, as this class is particularly infamous. Due to their utter contempt for all teachers, the class' students use psychological warfare to mentally break any new homeroom teacher they get, forcing them to quit and leave school. However, Onizuka isn't your average teacher, and he's ready for any challenge in his way. Bullying, suicide, and sexual harassment are just a few of the issues his students face daily. By tackling the roots of their problems, Onizuka supports them with his unpredictable and unconventional methods—even if it means jumping off a building to save a suicidal child. Thanks to his eccentric charm and fun-loving nature, Class 3-4 slowly learns just how enjoyable school can be when you're the pupils of the Great Teacher Onizuka. [Written by MAL Rewrite]

Akutsu Masatora is a demon who has infiltrated a high school in the human world. His goal is to find candidates to aid Hell in the fight against their natural enemies, the angels of Heaven. Assigned a seat next to Lily Amane, another student who transferred here not long ago, Akutsu falls prey to her beauty and decides to recruit her to his cause. But there's more to Lily than meets the eye, and Akutsu not only finds himself an accomplice to one of the very enemies he is supposed to defeat, but he also might have developed feelings for her.