Tutoring Restricted Area

I'm a... First-level thug at a company disguised as an education company? I don't know when, I lost my memory. I was hanging around in this company as an ordinary tutor, and I always thought I was a complete loser - until that day, I discovered the truth about the company. There are not only thugs here, but also three levels. The strongest group should have eleven people, but now there are only ten left. Their captain disappeared some time ago. No one knew where he was, and no one mentioned his name. During a certain mission, as an ordinary tutor, I pried some clues out of a suspect. But before I could ask further questions, a knife from "one of my own" swiped the other person's throat. And the daily life I once thought was completely shattered after that knife.