Hm, I'm gonna take a guess and say that when they get to Tokyo, Hiromi will make them kill themselves or something that reverts all the things the zombies are doing. Way too simplistic, but I don't really know what else they could do.
The paneling in this chapter was 11/10. Like they were sitting next to each other.
And it's interesting to learn what the chain of power is. Somehow, Hiromi has ended up as the Queen Bee? The question is, will she remain fully in control?