It's not for everybody and can make plot twists or character developments feel close to disingenuous, but Matsumoto is a seasoned mangaka, both by now and by the time this was in publication over a decade ago. With that in mind, it's clear that him not spoonfeeding ideas and themes isn't a result of laziness or incompetence, but because he expects his readers to pick up on what he's putting down, no matter how sly he does it. I do not believe I picked up on most of it from my first read, which isn't common in manga as a visual AND literary medium by default. Whether you're okay with this or not is extremely subjective to the point that deciding on recommending this to people is pretty fruitless.
However, I'm giving a recommended rating over a mixed or not recommended because the series is short and sweet. There are no pacing problems, and with only 43 chapters, it was almost impossible for it to overstay it's welcome even if it tried. And besides, if you're looking at reviews for this series, it's very likely you've read Freesia or other related seinen and are looking for stuff to scratch a similar itch. This *will* do that for you, but don't expect too much. This is a great refresher/break series to read between larger ones, but I imagine you'd be hard pressed to find *anybody* saying Alice in Hell is amongst their favorites.
8/10 for a thoughtful read, 6/10 for a casual one. You'll eventually find solace as a careful reader in the latter half of the series, which really starts to drive home the hanging themes and questions that the first half set up. As a casual read, there are some pretty fun and creative sniping moments, on top of small-scale war skirmishes here and there. It's easy to be very weirded out by the plot twist surrounding the protagonist Shuu if you weren't prepared for something like it, though, so keep in mind that it'll try to get a little heady on you eventually.
