Araigne

There's a man in your town who saves it from villains or simply helps people. They call him Araignée (spider). No one ever saw his face, as his face was hidden behind a mask. No one knew where he came from or how he even came to be.

You're a student living in an apartment. You have a strange neighbor you've never seen. One day, late at night, you were walking home when you entered the entryway and saw this spider enter the apartment across the street. He didn't notice you. The next day, as you were leaving the apartment to go to class, you saw the neighbor from that apartment. You left without saying a word.

Back at the university, during class, a guy bursts into the classroom—that neighbor. He's announced as a new student and sits down in an empty seat.