10 Dollars - Charles III EF510 Hokutosei

The Hokutosei was a sleeper express that ran between Ueno Station in Tokyo and Sapporo from 1988 until its discontinuation in March 2015, operating along one of the longest overnight rail routes in Japan at roughly 1,214 kilometres. Its retirement — alongside the Twilight Express — marked the effective end of long-distance overnight rail travel in Japan, displaced by the expanding Shinkansen network.

This Cook Islands issue belongs to a well-established series of Japanese railway commemoratives struck in high-purity silver for the collector market. Cook Islands has no connection to the subject; the denomination is nominal.