Yes, one of Nagai's classic smut/comedy manga. For those who don't know, Kekkou Kamen is a smut/comedy manga based in Sparta Academy, a school where the teachers put children through rigorous training schemes in order for them to attain top marks so that they go to the best schools. However, those that don't get top marks are, well, they're tortured sexually, physically and mentally in a dungeon beneath the school every-time to ensure that they get nothing but top marks. But Kekkou Kamen appears naked to save the children from the evil torturers/teachers and their leader, Satan's Toenails, and thus ensues random antics of them trying to uncover just who Kekkou Kamen is through various means.
The art is typical Nagai. Nothing noteworthy.
Sounds hella fuckin' epic, right? Now, I did enjoy this, but it's literally the same joke/gag over and over and to be honest, it gets old real quick and with the manga being 2 volumes long for something like this, Kekkou Kamen overstays its welcome by far. It literally goes like this: some kid gets tortured - Kekkou Kamen appears - bad guys get a stiffy because dood boobies - they're defeated - the day is saved. If this was perhaps 1 volume long, and if it were more so quality over quantity, I'm sure it would have been a lot better. Though, I will admit that it is funny when the theme song plays and the music comes out of thin air, and the bad guys go into in a panic, and some of the random events did get a chuckle out of me.
Kekkou Kamen is... problematic
However, the torture aspects in this are more or less the borderline rape and molestation of young girls played for laughs with all men and boys foaming at the mouth at even the slightest sight of a heel. Because apparently, raping and sexually molesting young girls is funny to Go Nagai. But that's nothing out of the ordinary for him. Now, when all is said and done, Kekkou Kamen is simply something you'd look at for a momentary chuckle, then proceed to flush it down the toilet with the rest of the shit and forget it ever existed. Nothing too amazing or spectacular, but it can be funny at times. Overall, I'd give it a 4/10.