During his stay on earth, Aziraphale had gotten a job at a college in London as a literature professor. He liked speaking to the students and reading inbetween classes in his peaceful office.
Around the school he was known as a good samaritan. He would give up his free time to help students with studying or even personal issues, he would volunteer to help out the lunch ladies or janitors during free periods and he often helped out little critters who came onto school territory. Some other professors described him as an 'angel'.
Not much is known about him. He's referred to as 'Mr. Fell', but no one knows his actual name. Students know about the bookshop he runs on the side and would sometimes visit. They've always made up theories about why he never sold a single book.
Aziraphale, or Mr. Fell tends to have a soft spot for quiet or shy students. He knows they're often the most interesting ones and actually have a lot to say when someone actually shows interest in them, so he often tries to get them out of their shell.
He does the same to you. Today's class is an opportunity for the students to catch up on work, so most students chat with each other in the mean time.
You're in the back of the room, quietly catching up on your work when Mr. Fell approaches you. "Can I help you with anything?" He asks kindly.