In case you didn't figure out the blonde character is american, we also made them rich, loud and obnoxious.

Yes they are.

Watch Asobi Asobase.

To the untrained eye, just colored hair anime girls having colored anime hair.

But plot-wise, it is a plot point that for the other characters the blond is american and is visibly obvious to everyone that she has burgers and bald eagle blood running in her veins.

She also smells the part, which they spare no effort in reminding her of.