Gold Kingdom and Water Kingdom

Long long ago, there were two neighboring nations who were on bad terms."The grass from your nation keeps getting into mine every single day". "The sound of futons getting hit in your nation is annoying". They argued over dull subjects like these. At long last, they got into a war because of the dog shit incident, And in the confusion, the gods intervened and mediated a truce between the heads of the two nations. This is what they said to say: Land A will send the most beautiful girl in the land to Land B, And Land B will send the smartest boy in the land to land A, and they will both be wed.

Note: Ranked #1 Kono Manga ga Sugoi! 2017 (Female readers)