In May 2026, three major domestic marathons (Tohoku, Hokuriku, Kyushu) simultaneously announced a 'Japanese Monetary History' collaboration. All finishers receive a commemorative medal modeled on Edo-period coin designs, while dedicated exhibition booths and expert mini-lectures line the course. The combined regional economic impact is estimated at over 2.8 billion yen, attracting attention as a new visitor pathway for the old-coin market.