This manga is stupid. Like, really stupid.
...and it also happens to be one of, if not the best shounen I've ever read. However bonkers this series is, the jokes land well. And even more- the big, emotional/plot moments make you question whether you're actually reading a comedy.
I feel like all of this is best summarized with this series' main villain.
"Ah, I just realized... we were just 'bad'... this soft-looking man... so different from the other prisoners... he was the true... evil." - a prisoner
This villain has no business being in a comedy manga. He belongs in a psychological horror manga instead. Once you see him, you'll understand. He's irredeemably evil- there's no gray zone with him- but it's not in a cartoonish way. It feels real.
For the most cartoonish and child-friendly looking shounen of recent times, this manga tells the darkest and most realistic message about friendship- that it's impossible to become friends with everybody- and if you try, it'll only come to bite you in the ass some day.
Instead, keep a small group of good friends that you can trust.