I can't figure out the thief quest. I feel like I've spoken with every character in the school and havent made any headway
If did everything right and reach a scene where people surround a guy. When confront them and given two options, pick the "show fangs". One of them will stop and introduce themself and explain. You can then meet the person in room next to the teacher's room and talk to them. Do continue to investigate but remember to talk them every single day before you finish the investigation.