It's not terribly uncommon for light novel adaptations to just be short introductions to the setting, to drum up interest in the novel. The anime adaptations are like that pretty often too, "Ah you're hooked now, go buy the novels for the rest." About 12 chapters would really fit that bill pretty well in my experience of seeing such things. Granted, whether it's that or the axe is pretty unimportant, the end result is the same.