The sea surrounded Japan's islands made it easier for people in ships to travel along the coast and from island to island. The mountains made it hard for enemies to attack Japan. The samurai were good warriors.
Japan developed its own independent society with its own religion, art, literature, and government. About 20% of Japan's land can be farmed on because of its mountains. Japan is surrounded by water so they can trade goods in ships.
The Emperor and Shogun were the highest rank person. The Emperor was the leader of Shinto. Shogun was the the leader of the army. There are over 3,000 islands in Japan.