When Mr. Satou, a company employee at the world's largest electronics company, is called upon by his boss to tutor his only son in exchange for a high ranking position within the organization, things couldn't have been peachier. At least, that's what he thought... Little did he know that his student was Ichirou Matsushita, a young boy with the mind of a genius and a terrifying hidden agenda. It doesn't take long for Satou to realize that he is the second home tutor in as many weeks that has been sent to teach the little boy. What's even more unnerving is that the previous Tutor's whereabouts appear to be a mystery... The little boy's true identity is revealed when he puts Satou under a curse, turning him into a lizard man and making him one of servants. Little Ichirou Matsushita is none other than "Akuma-kun" boy genius and master of black magic. His goal? To open the portal between hell and earth, summon forth hell's most powerful demons, and enlist their help in taking over the world!

The ghostly Hanako-kun and his mortal assistant, Nene Yashiro, usually have their hands full resolving various supernatural incidents in Kamome Academy, but how do they spend their time when they get a break from all that? Come and watch the characters of Toilet-bound Hanako-kun play games, get sick, change genders, and discover world-shaking secrets during their laid-back after-school hours!

Kazuki Yoshino and Yuuya Niyodo are idols who make up the duo ZINGS. While Kazuki gives his all in every performance, Yuuya views the job as just another means of making money. Yuuya's apathetic attitude toward the fans and inability to take his job seriously causes his manager to give him an ultimatum: unless he starts putting in more effort, he will be fired. Backstage, Yuuya meets Asahi Mogami, an idol dressed in a colorful costume. Asahi would have had a bright future ahead of her—had she not died a year prior. Even as a ghost, Asahi wants nothing more than to perform for fans again. When she finds out that Yuuya does not hold the same passion for the idol life that she once did, she is overcome by a fit of rage and demands that he let her take his place. In a strange twist, Yuuya wakes up to find that Asahi has possessed him and can do what he is too lazy to do himself. With Asahi performing for him, Yuuya thinks he has a ticket to an easy idol life. However, Asahi has other plans. Though she is no longer alive, she wishes for Yuuya to find the ambition that she still has. Together, she wants them to become the best idol the world has ever seen. But can an unmotivated man like Yuuya ever care about anything besides money?

The fate of mankind is doomed in the early 21st century due to losing "purana," an essence of living force supporting all life forms. Not willing to witness the extinction of mankind, a vampire named Duo disclosed the secret of purana to humans, saving the latter from destruction. However, just like Prometheus in Greek mythology got punished for bringing fire to mankind, Duo is punished for breaking the taboo. The vampire sent to punish him is Zieg, Duo's best friend, or, more than the best friend.