-!Spoilers bellow!-
-I will only talk about the ending-
(sorry for the bad english, I am from south America)
Prison School is a masterpiece 10/10. Great art, great characters, and a marvelous story.
Well yes it has some flaws, but most of the complain i see is from the end of the series, I HATE IT, i almost screamed in frustration when i read that.
But its the perfect ending, and is the fact that every one hates it that make it so brilliant, through the manga we follow the story of 5 douche bags, they are NOT HEROES, they only make fucked up shit and the plot only begins because they get caught doing literally sexual harassment, and yet, we sympathize with they story, we are mostly on their side, but what about the other side?
The other side of the spectrum are the girls, it doesn't matter if they are a friend or a foe, the boys are always trying to abuse or benefit from then, but it doesn't make the girls a victim, they are as bad, if not worse than the boys. The 5 are isolated, they are exotic animals to the women there, and they keep "messing up" (for a lack of better words) with the boys, the President puts then in horrible situations to her own benefit, like the bonner episode, she sacrifices everything to her own good. the vice pres. keeps physically abusing the 5, and Hana is the worse, she keep trying to shame Kiyoshi after the accident, she could forgive him and forget what happened, but her own pride keeps her going, the same pride that is responsible for this bitter ending, and eventually she herself succumbs, when she mistook the first sexual experience she had for love for Kiyoshi.
What is my point you are asking, what this rambling is for? My point is: EVERY ONE OF THE CHARACTERS ARE A BUNCH OF DIPSHITS, there are no one that is entirely good or bad, there are no hero nor villain, they are people, even worse, they are TEENAGERS, they have flaws, although the boys have known each other since childhood, they constantly backstab each other for own benefice, the girls have a superiority complex so great that they still hate the 5 after all the sacrifice they have done, and yet there are one person that is different, one person that through the story remained pure, Chiyo.
I never liked Chiyo, in a cast full of interesting and well written characters, i always tough she was extremely bland. After all the shit Kiyoshi have done, she still likes him, she doesn't complain, her personality is being good and comprehensive, but she isn't a god, and she finally breaks in the end.
The ending is great, because the protagonist *doesn't* win, he losses and deserves to lose, because after everything he went through, he still is a bad person, even he admits: "I am a coward and a pervert, a sick wimp". And being a son of a b*tch, he gets what he deserves, but still, WHY THIS MAKES EVERYONE SO FRUSTRATED?
Because we sympathize with Kiyoshi, we sheer for the bad guy, that's why we hate the ending, because it is a final flip off of the author, not for the charterers he created, but for us, the readers, you need to have steel balls to say a" Fuck You" to your readers, and the worse part? we deserve it.
The ending is great.