1-nen A-gumi no Monster
The monster of 1st grade, class A.

Edit

In short, a masterpiece in the unfortunately very niche psychological thriller genre.

One of the few mangas where actually every action makes sense from each characters viewpoint.
Additionally, the author manages to keep it interesting throughout and not slow down by fillers. He is just getting more extreme with every chapter as the students try harder and harder to get rid of the teacher.

With only 15 chapters out as of the time of writing this, it has already crafted a rich backstory with the darker aspects of human psychology at its core.
This certainly is not for the usual target-group of mangas and many will simply not ... even have the knowledge to be able appreciate it for what it is, but this does nothing to deter from the immense effort put into this piece.

This one will develop into a hidden gem for sure.

This sucks. This manga could've turned into something great but it didn't. The potential of a classroom full of sadistic girls could've been an actually good manga and I had high expectations, i was disappointed however.

The plot was fine, i liked it at the beginning but it quickly turned downhill from there. It was WAY too fast paced and it's plot twists just seemed like a quick hook to keep the reader from falling asleep. The main character didn't even seem like a main character considering the fact the whole manga was focused upon the SIDE characters. The manga was also a bit confusing, ... it was drenched with edginess.

The only good thing in the manga was the slight mystery and art. The mystery was what mainly kept me reading, although reading it was boring I seriously wanted to know how it ended.

Overall, I wouldn't recommend this unless you have spare time to waste and have nothing better to do.

It's just a juvenile highschool drama, with a rather dumb plot and characters that are too edgy. Main characters are super cool and super pretty and super evil. Plot development is primitive and story's shortcomings are covered with harem-like scenes.
Storyline focuses on dreadful bullying and violence.

Started off rather well actually, with a teacher having to rein in a problematic class. That's a classic trope, but deteriorated into romance, bullying, nobody-understands-me cringe pretty quickly.

Recommended for enthusiasts of grim, edgy highschool dramas with pretty girls, that don't require you to think a lot.

Also, this is not a comedy. There were only a few gags early on.