Head upstairs and take the hallway passed room 2-6 and in to the door of the next room on the right (it won’t be marked like the others).
Talk to the teacher in the brown suit and he’ll mention someone going in and out of a room on the second floor. Step out of the infirmary and head north passed the exit, stepping in to the first room which is the Teacher’s Lounge. You want to start working on this as soon as the game starts and you have control of your protagonist in the infirmary. If you’re interested in getting him in to your party, prepare for a little bit of traveling around the map and going through some hard times with only four characters, but the end result is definitely worth it!
Numerous FAQs on the internet have the wrong information for recruiting, in my opinion, the best of the secret characters in SMT: Persona – Reiji.