Four Japanese symbols - Kuan Ei Tsu Ho /(square-head Tsu) / Blank. 23mm, 2.41 grams. Tokyo mint, issued 1740-1860. Hartill 25.51-25.53; Krause C#-; "Coins of Japan" #49. Most Japanese coins are very rare. These coins are, however, common - they were inspired by the Ming dynasty cash from China. "Kwan Ei Tsu Ho" means "Universal Treasure of Kwan Ei", "Kwai Ei" being the era of "Permanent Libarality" that began in 1624 and lasted for 20 years. The Kuan Ei coinage was issued for over 300 years at numerous Japanese mints - hundreds of varieties are known that circulated all over Japan.