To be honest, I'm the opposite. I actually prefer how it is now to how it was portrayed in the one shot... I mean the one shot is kind of amusing, but in my opinion it's not as funny as the actual story turned out to be.
I see your point but I bet the one-shot was made because in his mind it was suppose to be a serious manga. Probably changed his mind before serialization starts. Well, the story is interesting tho.
Given the authors other works I don't think he was trying to be more serious, he seems to prefer comedy with traces of seriousness more than anything.
OK SO I read the one-shot and then the first chapter. You see, sometimes mangaka makes one-shot to see if their story would sell or not and wow I was hooked on the one-shot so Im trying THEN! the chapter 1 is HORRIBLY disappointing. HOWEVER, I shall continue reading to see if I like it or not cause I hear this is a very good one but I am already disappointed by the big changes made between one-shot and chapter 1.