Why doesn't Ojisan's death get any attention? Alpha is shown getting emotional over the littlest of things, so it's weird that the passing of one of her best friends wouldn't affect her. A chapter where she reminisces about him would have sufficed, really. The same holds true for Sensei.
Both Ojisan and Sensei each get an Obi-Wan Moment chapter. Chapters 130 and 132 respectively. You can clearly feel they don't expect to live much longer and bid Alpha farewell.
With humanity declining this much, how are they still getting gasoline, electricity and coffee?
Alpha can hear customers coming from hundreds of meters away, yet somehow she never hears the mail being delivered.
What evidence is there that humanity is even in decline? I know that several characters muse about this being the twilight of humanity, and there is evidence of a recent ecological disaster, as well as climate change and rising sea levels. But there is no reason why the Earth wouldn't eventually reach equilibrium with at least a few groups of surviving humans (as it has several times throughout history). Small towns like the one Alpha lives in are becoming deserted as people die or move away, but the cities are still populated, people are still having children, and the earth is still producing food. It doesn't seem like humans are going to become extinct any time soon. There's no mention of a global pandemic ravaging the current population, and humans seem to be getting along pretty well with eachother. If anything, it appears that human civilization is at the bottom of an upswing in YKK; slowly rebuilding itself after the recent implied ecological disaster. Humans are a resilient bunch, there's no reason why they wouldn't be able to pull through.