First few chapters were good, especially the low key attitude of Asahina... by chapter 7 it's a bit different, I'm tiring of Asahina casually commenting on society/people in an implicitly condescending way while the other "main" male lead does nothing interesting.
In the end, still too early to judge, but I feel that this kind of series doing well hinges on how well the other 3 protagonists are able to serve as interesting components of the story. I'd be disappointed if they're just emotionally conflicted kids while Asahina is the only one able to adopt the new common sense. So far, no clear foreshadowing that would hint at their future roles.
Edit - dropped after chapter 9, the narrative tries to be deep but sort of comes off as hypocritical/preachy.
Only a few minutes into the disaster and they're already taking advantage of people's kindness just so they can deceive others into letting them loot a store. 2/4 of the kids being deliberately characterized as stupid/naive all the time bores me, too. Something like Zom 100 is much better than this.