I get that Hiro isn't supposed to really be all that sympathetic as a character. He's selfish, he's vain, he treats women as objects (he tries to cheat on his girlfriend in the early chapters), and he's overall cowardly/indecisive. But it's like the author set him up to go through an actual arc, but at the end, he's the same kind of guy he was at the beginning. He has no guilt over the women that loved and sacrificed everything for him. Yeah, the women in his life weren't all that great, but they at least tried to atone for their shortcomings (save for Harumi, yeah she wanted the other girl to die, but she's a 15 year old kid who was in love with Hiro and jealous of the other girl. Every girl around that age would feel the same). There was no conclusion between Hiro and Harumi. Someone he said he was in love with and it was clear she was in love with him. Harumi was also the only one to do something selfless for him (picking up his things in the forest). But he doesn't even care that she's gone and he doesn't even attempt to look for her. When she was picked up, he didn't know she was absorbed, so it'd stand to reason (to him) that she was still near the monster. But he doesn't even look for her. He just goes back to talking to himself. I don't even care where the virus/infection came from, because, to me, it's not about that. It's about his journey and growth (which he has none. In fact, he's regressed further). It's shown in the story that being absorbed can be reversed (Hiro was absorbed and so was Auntie) so this couldn't be done with Harumi? Wasn't she the catalyst and controller of the hive? The story doesn't even talk about this. It's like the author lost focus or sight of what made the story so good to begin with. It's so frustrating with these manga because it's SO GOOD up until the final arc, then it loses focus or the author stops caring.
I also don't understand how Hiro having a 20 gauge over/under shotgun would have made him this powerful guy. Okay, Japan has strict gun laws and most people don't have access to them, but the SDF does. They have AR's and sidearms. No one thought it would be beneficial for them to loot SDF bases/American bases/police stations/etc for their armories? They'd have access to far superior firearms than a crappy 20 gauge over/under and a single shot bolt action that doesn't even have rifling. Hiro walks past a US Navy AIRCRAFT CARRIER and doesn't even mention that those things are like floating cities that include massive amounts of armaments and weapons lockers. Yeah, they might be a hotbed for zombies, but that's one of those things you at least check out because the reward of getting into them is so freaking high. SDF's soldiers, upon being turned would have dropped their rifles. Go pick them up and use them if you can't get into the armories. With power going out, the maglocks on the armory doors would have been pretty simple to get into. Guns aren't THAT rare in Japan. Yeah, they're not as available in, say, the United States, but there are plenty floating around in Japan. Making them be almost mythical is just stupid.
Hiro also operates under the delusion that he's going to be rescued 6 months after that big monster died, but all he had to do was some quick math to realize that no help would be coming. Ever. The infection reduced the planets LARGEST CITY to a population unable to sustain itself a fraction of a fraction. If Tokyo was a baseline to go off of, every other major city on the planet would have been depleted to almost nothing, so no help would have been arriving. The population would have been lower than it was in the middle ages and it would have been likely that other countries/cities wouldn't have been able to stop their own big monster things. This is never expanded upon nor talked about.
