Their isolation affects how they view other countries and they're not influenced by outside cultures other than their own. their culture is very unique. it helped their economy because of long periods of piece and in a bad way they had little trade with foreigners, overtaxing and used rice for payment.
The isolation affected social structure because they didn't know.They could change positions in the feudal system.
The isolation affected there culture because they made there own unique culture from the outside world.The stuff came out was sumo wrestling, painting etc..
There are many more that has been affected but ill only list out 2.
