Dean and Sue Zemke

Prior to the Meiji period (1868-1912), last names were rarely used except by the Samurais, noblemen, merchants and some artisans. The commoners which made up the vast majority of people in those times were referred to by their given name and the area from which they were from. During the Meiji period however, the government with endorsement from the emperor made it mandatory for everyone to select a family name using a list of preauthorized Kanji (Japanese characters).

The majority of Japanese surnames consist of one or two Kanji symbols most of which are geographical landmarks such as river (kawa), mountain (yama), or forest (mori) and adjectives describing the landmarks such as one (ichi), small (koba), or bamboo (take). In Japan, it is customary to refer to someone by their last name even among friends. Similarly when writing a person's name the last name always precedes the given name. 

http://www.japanese-names.org/japanese-last-names.php