Sai Akuto aims to become part of his country's highest order of magicians and contribute to society as one of its clergy. On the day he is admitted into the Constan Magical Academy, his aptitude test predicts the following though: "Future Occupation... Devil King". Thus begins his difficult school life in which he is resented by the combative female class head, Hattori Junko, desired by a girl with mysterious powers, Soga Keena, and guarded by a beautiful female android, Korone.
The story takes place in the early summer of 2015 and is set in the city of Tachikawa, Japan. The city is populated by people known as Gatchaman, who are warriors that fight in special reinforced suits that are powered by the manifestation of spiritual powers of living beings called NOTE. Enter Hajime Ichinose, a 16 year old energetic high school girl who is obsessed with collecting day planners and stationary. She is chosen to become a Gatchaman and tasked with the duty of fighting a mysterious alien life form known as MESS.
A year has passed since the "Tachikawa Incident" in summer 2015. CROWDS -- the system that turns the mentality of humans into physical form that Berg Katze gave to Rui Ninomiya after extracting his NOTE -- has spread among the public. Prime Minister Seitar? Sugayama backs the plan, but not everyone agrees with his policy, and a mysterious organization attacks Sugayama's vehicle, marking the start of a series of new conflicts.
Mankind has developed superpowers known as "Quirks" with 80% of the population having some kind of superpower. These new abilities see the rise of both superheroes and villains. A prestigious school known as the The Hero Academy trains superpowered hopefuls into the heroes the world needs. Middle school student Izuku Midoriya wants to be a hero more than anything, but he's part the 20% without a Quirk. Unwilling to give up his dream, he plans to take the exam and be accepted into a high school for budding heroes. Through a series of serendipitous events, he catches the eye of the greatest hero, All Might, who agrees to train him.
One-Punch Man is a super hero who has trained so hard that his hair has fallen out, and who can overcome any enemy with one punch. However, because he is so strong, he has become bored and frustrated with winning all his battles so easily.
In Oshima the happy, carefree 14-year-old Akane Isshiki lived a poor but well-loved life together with her reliable little sister, Momo, who does all the housework, and her grandfather, Kenjirō, a genius inventor who only created useless devices. When the weather is clear, they can see the artificial island, Blue Island, across the sea. In the center of that island rises the revolutionary Manifestation Engine, a discovery that solved the world's energy problems, and leads to some major problems.