Unknown Japanese coin of the XVIIth Century

Obverse	Reverse	Inscription

In the KMXVII Catalog I found the key to dating 'ichi bu' and 'ni bu kin' (sort of old Japanese coins), that is placed at the right part of shown item's obverse.

• Shotoku period (1714)
• Kyoho period (1716-1736)

Character for the Shotoku and Kyoho periods are not era marks but are varietes of writing mint mark names.