The coin which is thought to have been minted around this time was a so-called Nisuiei because the top part of letter '永' looked like '二' (ni), and it is believed that a letter of '三' (three) marked at the bottom on the reverse side indicated the 'third year of Kanei era,' the year it was minted.
このとき鋳造されたとされるものが、いわゆる二水永（にすいえい）と呼ばれる「永」字の上部が「二」に見えるものであり、背（裏面）下部には「三」と鋳込まれ、鋳造年の「寛永三年」を意味するといわれる。