I Didn't Choose the Gangsta System, the Gangsta System Chose Me

Joren "Horen" Vierei has an intimidating appearance. In compensation, he has developed a kind heart: helping people in need, gentle to his surroundings, and always wore a kind smile. Everything was normal until, one random day, a voice entered his head.
[Congratulations, you are qualified to receive the Thug System. Do you want to accept? Yes is the only answer.]
"Huh? What the-"
[Initiating transition. Joren Vierei is now a Level 1 Underling.]
Follow Joren as he got abducted by a secret society after determining that he is an [Abnormal], bringing him into a fantasy school full of magicians and mythical creatures.
Encounter bizarre situations and figure how Joren will get out of the unwanted life he was forced to have.