I assume Hajime gave Misora an early sketchbook. The beginning of the story, that is. It would explain why the drawings are so bad, assuming he never redrew them. Otherwise after 3-4 years of consistently drawing, if he's still that bad, he's a rare person of zero talent even constant practice can't fix, to any degree. I hope that's not the case. I find stories of extreme inequality inherently flawed, unless it's something that couldn't be avoided realistically or it simply doesn't matter, like if the main characters have different hobbies/professions/goals. One might say perhaps the dude can write a masterful story despite not being able to draw it, but can he? The manga most certainly hasn't indicated it would be a great story. What little we have seen makes me think of a cliched, run-of-the-mill fantasy setting, which makes sense since it was created by two late elementary/middle school kids.