If you've read "Tomie" by Junji Ito I think you'll enjoy this show. It gives off the same vibes and they even look similar. It feels like they have taken influence from Tomie but I'm not sure if that's true. Just as Tomie mysteriously appears and causes mayhem, so too does Nanno, but just in schools.

I love mysterious, psychological type of shows so if you are into that I recommend you watch this. Every episode has its own concept (Kinda like Black Mirror) and I personally found them all extremely enjoyable.
Theres a lot of suspense but not too much that its off-putting and the way it was shot and produced was just amazing and it really added to the tense atmosphere.
The one thing I did not like was that it was kind of extreme and at times I was a bit confused... but don't let that stop you from watching since its certainly worth watching!