Sometimes I wonder if the synopsis really is correct for this manga (unfortunately it is, it's on the official JP raw site...) because this is chapter 2 now and we still haven't even begun to touch the events described in that. Well, I just hope whatever is described happens before Volume 1 is over. Spoiling the contents of Volume 2 or beyond for the synopsis would be astonishing, and stupid for the publisher to do.
The synopsis prepared me for a decoy protagonist scenario and/or a betrayal event but I still haven't a clue as to who this alleged "true hero" is supposed to be.
So are we really sure the two idiots in his party are humans and not demons in disguise? Just who disregards the value of human life in the freaking hero party? I mean, that party exists to fight for humanity, right? Huh.