Ansatsu Kyoushitsu

Synopsis

Before Nagisa completely gives into his anger, Terasaka throws a stun-gun at him, urging him not to become a murderer and think about what's truly important. Despite being heavily beaten by Takaoka, Nagisa uses what he learned from Lovro to perform his secret technique; shocking Takaoka with a sudden clap before using the stun-gun Terasaka gave him to bring him to his knees, leaving him with the smile he fears so much before shocking him unconscious. Afterwards, the three assassins from earlier reveal the virus they used is nothing more than an enhanced food-poisoning bug that will wear off eventually, as they didn't agree with Takaoka's methods. The next day, after the affected students recover from their symptoms and Koro-sensei emerges from his crystallized state, the students makes the most of the remainder of their vacation before returning to school for the second term of their assassination classroom.

(Source: Wikipedia)