Very Holey The plot of this thing has more holes than a slice of Swiss cheese. This show is not bad, but it's far, far from great. It started off well enough, but the further it got, the more ridiculous it became. The last few episode are extremely frustrating because pretty much nothing makes any sense. I mean, some things didn't make much sense from the beginning...
(Why was there an infected rat in the school lab that didn't even have a decent lock, to begin with? Not like the biologist dude couldn't keep it at home. Why haven't they mentioned the fact that On-Ja was bitten in the very first episode? The nurse turns within minutes, but On-Ja hadn't even broke a sweat, and nobody, I repeat, NOBODY even mentions it later on, even though people knew about it. Some people get a crapload of infected blood in their eyes, nostrils, and mouths, but there is absolutely no effect, because apparently, swallowing, inhaling, or bathing your eyeballs in someone's blood does not deliver it to your bloodstream...? )
...but the last few episodes were just infuriatingly ridiculous (which I won't really talk about, 'cause it'll take forever). However, another infuriating thing is that this show has a higher rating than Sweet Home (AoUAD is 7.5., while SH is 7.3). How did that even happen?? Sweet Home was levels above All of Us Are Dead, and yet somehow it got lower ratings. Sigh...
Anyway, this show was not bad, as I said, and it was entertaining to watch despite everything that was wrong with it. It's definitely worth a single watch, just don't expect much from it -- it's nothing but some popcorn & bubblegum. Also, if you take a drink every time someone throws the bully off something, you'll be warm and very fuzzy by the end, so it makes it a decent drinking game.