Nagisa Shiota - One of the students in Class 3-E, Nagisa is seen as one of the weakest students in the class due to his small stature and mediocre physical abilities that are comparable to some of the girls in the class. He takes a form similar to an octopus with eight tentacles and his skin color changes depending on his mood. However, he is able to connect with each student individually, which is why all of his students respect him, despite knowing that he will destroy the planet in a year. He is dedicated to his task as a teacher and imparting his knowledge of assassination to the students, despite knowing full well that he is their target. Despite not having the intention to get killed, he offered to governments all over the world a chance to kill him under the condition that he is allowed to be the homeroom teacher of Class 3-E until the end of the year, when he will destroy the Earth by self-destructing unless he is killed. He is initially thought to be the perpetrator of the explosion of the Moon, which has rendered it permanently in a crescent shape. He is the homeroom teacher of Class 3-E of Kunugigaoka Junior High School. Koro-sensei - The main protagonist and anti-hero of the series. Furthermore, the misfits of 3-E soon find that the strange, tentacled beast is more than just indomitable-he is the best teacher they have ever had! However, the monster, dubbed Koro-sensei (the indestructible teacher), is able to fly at speeds of up to Mach 20, which he demonstrates freely, leaving any attempt to subdue him in his extraterrestrial dust.

When a mysterious creature chops the moon down to a permanent crescent, the students of class 3-E of Kunugigaoka Middle School find themselves confronted with an enormous task: assassinate the creature responsible for the disaster before Earth suffers a similar fate.

Assassination classroom season 2 dub