Koro sensei is a mysterious creature that blew up the moon adn threatens to do the same to planet earth unless the students from class 3-E assassinate him and recieve a 300 billion yen reward. He can move at mach 20 and isn't much of a pushover.Koro sensei is nice and caring but is also very quirky. Not to mention perverted when it comes to woman. He...does however have multiple voices in his head that talks for him so one minute he is nice and caring the next he talks like a gangster.Scary. VA must be able to do various different voices.