Mother coin, Provincial, Sendai, chief city of Rikuzen in northern Honshu, 1-Mon, ND (1784). 3.1250 g, Copper, 21.5mm. Obverse inscription: 'Sen Dai Tsu-Ho' (Top to bottom, left to right). Reverse: Blank. Note: This type is the 'bosen' or mother coin used in making the sand molds for casting iron 1-Mon (for circulation).