Gakuen Tengoku is a hot, steaming, pile of mixed up stories and characters from (mostly) better manga.

First, we have the "childhood first love reunion" manga. (See: Love Hina) This is the best story line, and almost works, but keeps getting ruined by the others. It's the reason I stuck with it as long as I did.

Then, we add in some "controlling sister (in this case cousin) trying to keep women away from her man". (See: Oniichan Control). In the 33 chapters I read, this part of the story was never fully developed.

We add in a little "student starts relationship with teacher". (See: Sensei; Hirunaka no Ryuusei). If the relationship weren't so sexual, so quickly, this might have worked. As it is, it's just uncomfortable.

Finally, add in the ever popular "boy rescues girls on the verge of being raped, who then fall for him" (See: About a third of all Josei Smut manga out there) This part of the story seems to be supposedly comedic... cause rape is funny? I have no idea who thought this part of the story was a good idea.

And all of this is happening at the same time, and with the same guy. The result? A hot mess.

And too much of this mess is just uncomfortable to read. The main character ends up looking like a jerk for sleeping with (and/or fondling) a wide array of women (many of whom are underage)--despite the fact that he is supposedly head-over-heels for his first love with whom he has just reunited. Then there is an actual of alliance of male teachers, at this all female school, intent on raping their students. The "hero" thwarts them... but never turns them in, cause you know, it's not like teachers raping their students is a crime or a fire-able offense or anything?

Look, some of the characters are interesting, some of the plot-lines are interesting, and as Borderline-H material I've seen worse. But the end result here is far from a good manga.