Japan... Perhaps there is no other such country, which for centuries remains a mystery to the whole world. Thousands of books have been written about samurai, ninja, kamikaze, many films have been shot, and although their characters have long since left the historical scene, not all of their secrets have been revealed. There are also no unambiguous and rational answers to the questions: why did the invincible Mongols fail to conquer Japan in the 13th century and why did it not become a Catholic country three centuries later?