Well, I would give the first episode a shot and plan from there. If you dislike the first episode already, chances are you won't enjoy the rest either. But, on the off chance that it's your type of humor, I'd say give it a try at least.

 

Excuse yourself. The bulk of the show's appeal is Kiyoshi's interactions with his supporting cast and his resulting character growth. That involves the above two elements most of the time, sure, but there are plenty of instances where it doesn't- see his earth-shattering revelation during the tits vs. asses debate.

And that's the greatest pull of the story, if you ask me. It runs on fan service and over the top prison culture, but the fan service is the exact opposite of traditional anime fare. Everything in Prison School is serious, especially when it's not. I think my favorite part of the manga thus far was a recent chapter in which (spoilers):

Spoiler

Kiyoshi spends twenty-something pages brooding over his place in life now that he's been peed on by Hana. How can he face the girl he likes, how can he re-integrate with society? He is literally suffering from PTSD.

The whole story is completely ridiculous but the mangaka refuses to acknowledge it in-setting. It's so good.