The trailer for anime 'Ansatsu Kyoushitsu' has been revealed. 

In the trailer, titled '3-nen E-gumi! Koro-sensei!', the students introduce characteristics of Koro-sensei, such as "He's slimy," and "He's rather caring." You can also see scenes of Koro-sensei moving at the speed of Mach 20 and the students planning his assassination. 

Anime 'Ansatsu Kyoushitsu' will begin airing on Fuji TV on January 9, 2015.

Source: Comic natalie