Kan'ei Tsuho: Possibly the Longest Enduring Coin Ever。Japan: Tenpo, Bronze 100 Mon, 1865, Ko Kaku type, bosen, 'seed' or。Kanei Tsuho, Japan, 1668 | National Museum of American History。Japan, Kan'ei Tsūhō (Copper) - 1700's - Edo Period - History Hoard。KAN'EI TSUHO, AIZU FUTONO MOTHER COINAll details in photos. Thank you