Search currents matter.
“And this is why sushi is the most Japanese type of food. It’s where rice meets fish: the rice from the continent, migrating from south to north through the islands, and increasing the population through rice farming in the Japanese plains; the fish from the ocean, with the nutrients moving from north to south, following the winds and currents.”
https://unchartedterritories.tomaspueyo.com/p/japan-geography