I have decent expectations for this Japanese Post-Apocalyptic series. The story adds some intriguing things BESIDES Technology. People have had to adapt, there's no computers or Systems, there's only the Fungal Growth. The MC dies in a train accident, revives DEEP within the Metro, and meets his sidekick, a cute squeakin little carbuncle.
All the hate and "headaches" people get from reading her "squeak" speech aren't looking at the quirks of characters. She's a literal creature who isn't a harem character(at least not yet with no chance of becoming a humanoid). The MC is relatable, he doesn't want to kill humans, but he still fought his way out of the metro, nearly dying time after time, to get where he is, trying to get back to human society.
Some of yall don't WANT to invest in another character with good morals. Go find an NTR and Evil MC series.