Yakuza from Another World

I was torn out of my native world in order to carry out revenge. Immediately, a simple choice appeared: either die under the feet of the bandits, or defeat them. I won—but I ended up pulled into another criminal organization. I guess I’m not used to it, because I was a hired killer even in my previous life, and now… The truth is, I’m still a schoolboy here—but that’s even better. Who would think bad things about an awkward, harmless lout?