Japanese characters in seal script (except for the first "Tsu") - Gen Tsu Tsu Ho / Blank. 24.5mm, 2.78 grams. Mint in Kyushu, issued ca.1580-1620. Hartill (Japan) #3.131.
These coins are associated with Kyushu, the most south-western part of the islands of Japan. These are also known as Kajiki-sen, after a village of Kajiki in Osumi province.