Yokokuhan - The Copycat

Yokokuhan - The Copycat summary:

The terrorist group "Shinbunshi" was punishing bad guys and distributing their actions on the Internet. Hanaoka Takeru, a high school student, is shocked by them and starts working as a copycat with his childhood friend, Endo Sota, and his classmate, Nishizawa Kyoko. The three begin collecting money from people in the name of "righteous loss" in exchange for punishing the bad guys and distributing the whole story on the Internet.The copycats become online heroes, and their activities continue even after the death of the real Shinbunshi. Eventually, the police begin to investigate them as well.