Japanese characters in regular script - Ko Yu Sei Ho / Blank. 24mm, 2.44 grams. Issued ca.14th-16th century. Hartill (Japan) #2.-.
Very strange piece with "Yu" looking like a little man. Bita-sen coins was produced for the local circulation, as well as for export and trade to various South-East Asian countries. Many bita-sen coins are exceedingly crude, like this piece.