As mentioned... Getting SAFE food AND water is the most important thing, cause water supply will cease and you dont have idea if the water supply will be safe to drink anymore after the day it happens even if running water still works.
If you had to go to Brazil, you could just buy a bunch of 20L bottles of water or hijack a water truck, but no, you had to go to Japan, now you can manage.
I forgot he was supposed to have a system… If you are going to incorporate zombies from other series, though please leave world war, Z out of this, I do not think anyone is prepared for those type of zombies
Nice chapter! I think the MC should be researching places that are outside of the main cities and are able to be self sufficient like a farm and stuff..