I finished this in a few days, it was quite a good read I must say.

Story
An supersonic octopus became the teacher for Class E, the worst class in a prestigious junior high school. The story is surprisingly fluent, there is little boring moments in the manga, like say in 1 chapter the teacher say he is going to prepare the students in their exam, the next chapter the exam is already finished. Unlike some manga where the fillers comes in and frustrate the heck out of the readers. The manga also take an insight in education with assassionation, how teachers can affect or influence his/her students, I have to say after reading this manga, I actually wants to be an educator in the future, really inspiring, kuro sensei(I read this manga in chinese, hope the name is correct) really deliver a valuable lessons even to the readers!

Art
Art is okay overall, some parts do look a bit weird but nonetheless, very readable and enjoyable.

Characters
With a class roaster of 28 students, I expected the author to not differentiate most of the characters. Oh boy was I wrong. Yes I do admit that some characters are more focused in terms of character development, but every single character is different from one another, and frankly speaking, in the later chapters I actually remembered their differences.

Enjoyment
Definitely a 10 considering I finished the manga in less than a week.

Overall
10/10 I loved it, would recommend to anyone.