The twelve Chinese characters that represent the signs of the Chinese zodiac are called junishi in Japanese. The junishi originated in ancient China. People observed that the planet Jupiter takes twelve years to circle the heavens. They divided the orbit of Jupiter into twelve signs by continuously observing its direction and position for years. Then, they allocated twelve characters to the twelve signs. These twelve characters were used with the ten characters called jikkan to represent years, months, dates, time, and directions. Jikkan and junishi combined together are called eto in Japanese. When the twelve signs of the Chinese zodiac were introduced to Japan, the Japanese allocated twelve animal names to the twelve signs. The twelve signs were designated ne (the Rat), ushi (the Ox), tora (the Tiger), u (the Hare), tatsu (the Dragon), mi (the Serpent), uma (the Horse), hitsuji (the Ram), saru (the Monkey), tori (the Bird), inu (the Dog), and i (the Boar). The junishi and the jikkan, which are called eto, are only used today to refer to the year, and therefore people immediately associate these twelve animals with the word eto.