I can thank this class for ending my fear of manga, though I don't know how much I'll be seeking it out in the future. I think the biggest effect might be a change in my attitude toward anime--before it shared an "it all looks the same--shouty" category in my brain, but now I'm growing into the stories and looking beyond the shouting. So that's nice.
After School Nightmare is an interesting digression from the previous books. I'm glad we're getting a glimpse of some of the weirdness--sexual and otherwise--that you don't get as much in American literature/comics and that are such a big part of manga. The main character is a high school student who is a boy from the waist up and a girl from the waist down. He lives as a boy and is happy to be one, but he just started his first period, and he's upset and fraught. On the same day, a mysterious teacher at his school takes him into the previously unnoticed "basement infirmary" and begins his new lessons, in which he and his classmates wander through each others' nightmares. In these dreams, each person is revealed and transformed into their most frightening self--except our main character, who already considers himself such a freak.
Two admissions, up front. One: it seems weird to me that, before puberty, you could call someone "a boy from the waist up and a girl from the waist down." I mean, if you're a girl from the waist down, up until you're 10, that pretty much makes you a girl, right? I thought that was a little inconsistent. Two: I'm not a big fan of dreams in literature. Dreams are boring and dreamy and all symbolic and junk. They don't generally drive me.
That said, I think that the complexities of our hero's situation (sorry, I can't remember his name) are fascinating to me, and I can see how they would be incredibly appealing to teens. This is about everyone thinking you're someone you're not, and being ashamed of who you "really" are, and hiding it. It's about coming clean or coming out or being exposed to a few people, and how that plays. It's about being the boy all the girls have a crush on, and one of the best athletes who quits the team because his period means he can't "really" be a boy. It's about being a boy who's sort of a girl who is lusted after not just by all the girls but by some of the boys, too. It's about how none of this stuff makes any sense, and you can't sort it out, and all you really know for sure is that if anyone finds out, you're a goner, so you'd better keep that secret like hell.
And then, it's about discovering power, being chosen for the special class of those who can or must do something dangerous and mysterious. It's about the sense that there's a layer going on underneath things that you don't really know about, but that's really important in the world--you can't graduate without it. (I know this feeling well; my whole adolescence, I was sure that everyone knew something I didn't. Really, up until a few years ago.)
As a metaphor, as a simplified story, this is the story of someone feeling exactly all those feelings of the teen years--only symbolized, simplified, and made easy to explain in three paragraphs. I can absolutely see why this book would be so popular.