Why do Germans and Japanese have identical beards?

This is a kind of sanitary beard, which was popular all over the world at the end of 19 and the beginning of the 20th century. It is not only found in Germany and Japan. The main reason why Hitler cut his sanitary beard was that the Bavarian Infantry Regiment 16, which he served in during World War I, was often attacked by poison gas. As a messenger, in order to wear a gas mask conveniently, he had to cut off the original moustache and replace it with a sanitary beard. Sanitary beards are quite common in the Soviet Union, and so is Kong Xiangxi, Minister of Finance of the National Government.