Imo I believe that the backstory can be the same (even though I hope it isn't) the manga can still be written and expressed differently and it won't be a ripoff. I agree with you on those types of backstories though.
This chapter kind of clears up some misconceptions and shows that they compliment eachother well as a couple and not just the dude simping for the magical girl so that's nice.
I believe it is
Tanbo de Hirotta Onna Kishi, Inaka de Ore no Yome da to Omowareteiru
I Found a Female Knight in a Rice Field, in the Countryside They Think She’s My Wife
But I might be wrong, there is less drama and less stuff about like the government and drama in it and is more SOL/cooking...
I was looking to see why there were so little comments but then I realized this was posted during the dark age of mangadex, but very wholesome chapter, even though I'm a few years late.
Good chapter, I'm scared about the drama that is probably going to play out in the future about like him thinking that she has a bf because of her acting work etc etc. But hopefully there won't be too much drama.