Japan and Korea both have similar pounded glutinous rice foods, known as mochi and tteok, respectively. The exact origin of mochi is unknown, though it is said to have come from China. The cakes of pounded glutinous rice appear to have become a New Year's treat during Japan's Heian period (794-1185). As early as the tenth century, various kinds of mochi were used as imperial offerings at religious ceremonies. A dictionary dating from before 1070 calls the rice cake "mochii." Around the eighteenth century, people began to call it "mochi." Various theories explain the name. One is that “mochi” came from the verb “motsu,” “to hold or to have,” signifying that mochi is food given by God. The word “mochizuki” means “full moon.” People of the west and southwest islands called it "muchimi," meaning "stickiness.
A match-box sized piece of mochi has the same caloric content as a bowl of rice. Japanese farmers are said to eat mochi on cold winter days to increase their stamina. Samurai took mochi to the battlefield because it was easy to carry and to prepare. The sound of samurai pounding mochi was a sign that they were about to go into battle.