Japanese characters in grass script - She Hei Tsu Ho / Blank. 24.5mm, 3.21 grams. Issued ca.14th-16th century. Hartill (Japan) #2.40ff.
This type was inspired by the Northern Song dynasty Tai Ping Tong Bao cash. Very neat piece with a triangle head on Tsu and right-pointing leg on Hei.
Bita-sen coins was produced for the local circulation, as well as for export and trade to various South-East Asian countries.