Is it good? This question is irrelevant. It just is. Ultimate Teacher laughs at "good" or "bad". It's a nonsense action comedy with mega-machismo, a human cockroach, girls' gym shorts turned into a weapon and a baddie who attacks by throwing coins at you.
To be honest, it's not that great. Absurdity is the point, though, and it's quite good at that.
We begin in a genetic engineering lab. To the horror of all concerned, IT ESCAPES! (We don't yet know what "it" is.) This is the future, i.e. 1991. We see a military recruitment poster inviting young men to join the army and participate in some unknown foreign war, perhaps suggesting some degree of dystopia.
Also suggesting dystopia is the urban warzone that is Emperor High, the worst school in the Kanto region. It has a cemetery for teachers murdered by students. Knock a hole in a wall and you'll get showered with skulls and skeletons. The students hold the school in a grip of fear and the only remaining teachers are all convicts or cultists, but fear not! Ultimate Teacher has arrived! He's gigantic, his name is Ganpachi Chabane and he talks like a villain from Fist of the North Star, except that he happens to be very silly. He's also played by Naoto Takenaka, who I hadn't known had ever done anime voice work (although among other things he's the official Japanese dub actor for Samuel L. Jackson). I love Takenaka. He's an award-winning actor, comedian, impressionist and director who's done hundreds of films and TV shows. If you've seen half a dozen Japanese live-action films, you've probably seen him.
Anyway, here Takenaka's pumping the machismo up to eleven, but with a character who talks complete nonsense half the time and makes squeaky rubber noises as he scuttles crablike along walls. After that, stuff happens. The plot's straightforward, underneath the silliness, but it has some mildly interesting fluidity in who's the hero and who's the villain. Who's the bad guy? Is it:
(a) the man who volunteered as a teacher at Emperor High and is trying to turn these psychotic hooligans into productive members of society,
(b) the gang boss who's very happy with the status quo and thinks the school's just fine as it is, or
(c) a scientist who did genetic experiments to make deranged human-insect half-breeds and then let them escape into the outside world?
The answer to this question will depend on how far you are through the OVA. The hero doesn't turn villainous or anything. He's still the same guy, with the same goals. (Well, ish. I don't think he ever tries to do any teaching.) The OVA just switches focus and starts presenting antagonists as the protagonists, either for laughs or from attention deficit disorder. Actually, no, on second thoughts I think it might be because one of those characters is a schoolgirl who at one point is glimpsed naked. Never underestimate the power of boobs.
There are two English-language dubs, although we're talking pre-DVD. Your choices are either YouTube or hunting down old VHS tapes. I watched in Japanese, obviously, but I understand that the U.S. dub doesn't seem to have realised that this is a comedy, while the U.K. dub is taking the piss.
Audience opinions have been polarised. Its humour's based more in absurdity than in character, but there's nothing wrong with that and there are people who've laughed their heads off at this. (Personally I thought it was sort of okay, although I don't imagine I'll ever watch it again.) Why did someone just go past on a camel? Don't ask. Why does Ultimate Teacher's ultimate attack involve an army of pelvis-thrusting men in girls' gym shorts? How did Ultimate Teacher himself manage to wear an infinite number of pairs? Why are those people singing? Answer: because it's funny. If you're in the right mood, anyway.