As of 2014 there are only 33 mega cities in existence. Tokyo is ranked as the top mega city in the world. Five of the top 25 amusement parks are in Tokyo. Tokyo has the most extensive urban railway network worldwide. Japan’s literacy rate is almost 100%. Sumo is the national sport of Japan. In Japan, slurping your food is a compliment to the cook. Tokyo has more neon signs than any other city in the world Tokyo is home to the world's most expensive restaurant Japan has one of the lowest infant mortality rates of the world.