I love this since it's such a bleak and hopeless story but I must point out that there was a very simple and very effective solution within reach of the teacher; call the cops. The minute that Cid told him about some dude in the woods, he should have just called the cops. They would've combed the forest so he wouldn't have to and he would have demonstrated to the parents that he was being a responsible teacher. Child abduction is one of the most feared anticipations for any parent, even abusive ones; he could have flipped the outcome of his situation into becoming a 'hero'.
Besides, they have a fence surrounding the basketball court but not the field? I see the people responsible for managing the funds for this school are fucking retarded, that says a lot about what the rest of the school board must be like. Now that I'm thinking about it, the protagonist deserved to get fired; despite the fact that the rumor wasn't true and he knew its actual nature, he should have anticipated that other people wouldn't.
The fact that there's random garbage littered about the forest reinforces what dipshits the school board is for not putting a fence up around the field, assuming that field is their territory. In fact, a lawn chair resting against a tree, facing the playground, implies that the kids are being watched, most likely by a pedophile if not a parent or both. Even if that's not the case, any of the kids could wander off into the forest and get lost or abducted.
Another hazard to consider is that since there's garbage in the forest that a kid might get injured fucking with it and if there's shit like a wheel and lawn chair, that means there's likely rusted metal objects that were dumped in the area; that means tetanus for the kid that cuts himself on the metal or puts it in his mouth.
At the very least, the teacher could have collected the junk and used/recycled/disposed of the shit within eyeshot from the edge of the forest. If another lawn chair appears, call the cops. If more junk appears, call the cops, only this time, call them for illegal dumping and child endangerment. The fact that the wheel and lawn chair aren't rusted over implies that that they were, at best, recent dumps and at worst, implies that there's still illegal activity ongoing within the forest.
In fact, by collecting the metal from the forest [the tire had the wheel inside it so there's no arguing against this point] he could take that shit to metal shops and make extra money from it. Huzzah.
Even despite the fact that the rumor was obviously bullshit, nothing was really done to prevent such a possibility from occurring, not in the fucking slightest. All the teacher really did was try to reinform Cid's classmates that there were, to his knowledge, men in the woods.
Fuck, telling other teacher's about the rumor would've helped since that would've meant that other people would know about it and it wouldn't look like a spontaneous fuck up on his part when the parents protested his conduct, that would have at least given him a chance to keep his fucking job. In other words, making the rumor as public as possible would've saved his ass, having the image of being overprotective is the best thing a teacher could have.
I only have one technical piece of advice; get a mic sock. I heard the voice actor blow wind into his microphone at the last line "there's a man in the woods". Getting a mic sock will prolong the lifespan of your microphone since it prevents both saliva and other shit in the air from entering the microphone and ruining it. Remember, pop filters work only as well as reflection shields; neither of them are omni-directional but your voice and dust particles are.