Hataraku Maou-sama!

[Ryllharu]

It also makes no sense how somebody like that could have become a maou in their home world. You'd think demons would be such backstabbing bastards that a doofus like that would have found himself killed twice over in no time by his own men.

It's not like he gated into Earth and then became a big softie the same day. He was still talking with authority and acting high and mighty that first night. He was suspicious of the food at first, and definitely didn't eat it (to the point where he later collapsed from lack of food), while his underling was already chowing down greedily. He planned, gathered an extraordinary amount of information from the cop he hypnotized so that he wouldn't arouse suspicion again as they settled in. At least give him the respect he deserves for that first night. While his underling was freaking out, he was calm and under control.

The thing is, they've been there quite a while by the end of the episode. You can't buy a fridge, a washing machine, and a bike after a month's salary working part-time. He's adapted. He has gotten used to interacting with the world they've ended up in, while his underling has been sent off to study, and has kept on task (though becoming a bit of a housewife) and remains calm and under control. So there is a bit of a role reversal from the beginning compared to the end.

So his ambitions have...suffered a bit from tunnel vision on his part of the duties. Which after all, is earning all the money so the two can survive. Someone like him falling so far and probably not even realizing it, I think that makes great comedy.