Go Nagai takes the anti-establishment themes from Harenchi Gakuen and Abashiri Ikka and turns them up to 11. Instead of students rebelling against their teachers, they're not even going to school anymore - they're literally at war with them, complete with machine guns and bazookas. And that's pretty much the entire story. We follow several intense skirmishes with the minimum amount of breathing space between them, just enough to put in a quick dramatic speech. Nothing really matters except for the carnage. And the carnage is as relentless and fun as it gets in one of these Go Nagai mangas. The guys get shot repeatedly, theirlimbs get torn off and their heads explode, they get set on fire and get their faces melted off by acid, while the girls keep losing the little clothes they're wearing or are captured by some sort of foul monster.

Not that it matters much, but the characters are pretty simplistic and they aren't developed at all, apart from one of them getting a somewhat goofy backstory. A Nagai trope I really dislike is introducing a female character as a more than capable badass, but then relegating her to the sidelines immediately after. One of the three main characters is exactly like that.

As expected from Nagai, the art is cinematic, dramatic and dynamic. This manga is basically a showcase of how well he can draw all kinds of different action scenes and they're often really impressive.
The character designs aren't very memorable and they don't set themselves apart from other Go Nagai characters, but I like the bushy-eyebrowed stock Go Nagai protagonist look.

Gakuen Taikutsu Otoko is basically all action and no substance, but it's breezy and entertaining enough to get a 7/10 from me on those merits alone. It's an extremely self-indulgent manga, but that's probably what makes it so enjoyable. Nagai felt like drawing it, drew and left it alone as soon as he's had enough (and without actually ending it, but oh well).