WOULD DEFINITELY RECOMMEND. I came across this show when I was running out of anime to watch (kind of fortunate given it was around exam period for me), and reading the review piqued my interest. I kept my eye on it and waited for all 12 episodes to be released, and boy am I glad I did.
I appreciate what some would call immature humour, that is, sex jokes (or any related "taboo" subject). But that is not enough to make me enjoy a comedy, what really sets a joke is the context, and Prison School has done so masterfully, there is amazing situational comedy to be found in every episode. There are so many examples of this, but to truly gauge whether or not this is the show for you, watch no further than the 3rd episode.
If you are not the kind of person to enjoy silly and cheeky sex jokes, then you should approach this anime with either caution or a sense of light-heartedness.
The creators of this story are so imaginative, some of the lines and explanations in the show are so completely stupid, yet somehow retain a sense of logic, which leads to some really memorable moments and great humour (e.g. the explanation of the evolution of breasts, and Kiyoshi's peeing stance).
There is but one complaint I do have about the show, yes, it is the ecchi. There is a ridiculous amount of boobage in this series, however, I managed to get over it for the sake of the comedy. If unnecessary cleavage and gratuitous up-skirt shots are a dealbreaker for you, then perhaps this anime is not for you, though I still recommend attempting to watch up to the 3rd episode; if you get that far and still do not appreciate the humour over your distaste for the ecchi, then you can honestly say that you did truly attempt to watch the show.
Though honestly, I have recommended and shown this anime to a total of 8 of my friends (so far), and every single one of them thoroughly enjoyed the show (even those completely against ecchi).
Personally I found myself laughing so hard and having to hold my sides from the pain, it was that good. I would give it a 9/10 overall.
Tl;dr
Great comedy, though excess ecchi may turn some away.
