Why the fuck would this guy, that was leading a horrible life in japan, want to go back? Masochism? He can stay here and get magic power but his first instinct is to return to his horrible everyday... at least listen and think about it for a bit, rather than immediately want to go back to the cesspit.
And why do we HAVE to have the ultra loser, to the point that 99.99999% of normal dudes are better than him, be the protagonist? Which is stupid anyway, since he's described as an ultra loser but his design is pretty normal anyway, It's not like he's terribly ugly or immensely obese or anything.
This manga is so full of horrible cliches... Sure art seems good but that's it.