解説Old 1 Yen Bank of Japan Silver convertible note - Watermark.jpg
English: Watermark of Old 1 Yen Bank of Japan silver convertible note. "日本銀行券" (read right to left, "Bank of Japan Note"). The oldest valid currency in Japan (as of 2011). First issued in 1885. Now defined as nonredeemable banknote by law. Legal tender.