“The fact that British technicians had been employed by the Lighthouse Department was a crucial factor in [Japan] adapting British practice in communications. Nevertheless, in the case of the postal service, the standard British practice of the day was to rely upon steam-driven railroads.
“Now, in the early Meiji period, [Japan’s] railroad network was in its infancy … and thus it was impossible to use railroads for delivering mail during this period. An interesting hybrid emerged, one that spliced earlier British practice onto contemporary British practice, and the amalgam onto Chinese practice.
“Earlier British methods using horse-drawn carriages were used to join some nodal points to one another. The human-pulled cart or rickshaw that had been developed in China – in 1870, under the Japanese name jinrikisha, it began carving a widening niche in the Japanese market – was used to supplement this form of [postal] land transport.
“… [T]he main factor underlying the rapid expansion [of the postal system] within Osaka is concentration of population in the great conurbations of the Tokaido belt. Establishing a nationwide postal system involved considerable fixed over-head cost, in total and a per capita basis. But the per-person fixed cost for building up the infrastructure of mail delivery within the Tokaido was far less.”
– Japanese Industrial History: Technology, Urbanization, and Economic Growth, by Carl Mosk, 2000
From the wiki: “In 1870, Baron Maeshima visited London to learn the workings of the British postal system. A year later, he founded Japan’s postal system in 1871. The first stamps were issued in April 1871. The intricate two-color design consisted of a pair of dragons facing towards the center, where the characters of value were printed in black. The denominations were in mon, which had already been superseded by the yen; the same basic design denominated in yen appeared in 1872, but was itself soon replaced by a new set of four designs featuring the imperial crest.
“In 1876, a definitive series was introduced, with a generally oval inner frame, and inscribed ‘IMPERIAL JAPANESE POST’. Japan joined the Universal Postal Union (UPU) in 1877.
“Japan’s first commemorative stamp, in 1894, marked the 25th anniversary of the wedding of Emperor Meiji and Empress Shōken. The first persons depicted on a Japanese postage stamp, in 1894, were Prince Kitashirakawa Yoshihisa and Prince Arisugawa Taruhito, honored for their roles in the First Sino-Japanese War.”