While most of the major powers of western Europe spent the 17th, 18th, and 19th centuries racing around the world carving out empires for themselves, Japan felt threatened by the influx of foreigners and ended up spending this period as one of the most reclusive nations on the planet. In the 1630s, a series of proclamations closed the country’s borders, marking the beginning of the period now known as sakoku (‘locking the country’) or sometimes kaikin (‘sea-restriction’). Non-Japanese-citizens were not permitted on Japanese soil; potential violators were warned that they would be subject to capital punishment. Only a small amount of trade with China, Korea, and the Netherlands was permitted, and the Dutch were restricted to Dejima, an artificial island in the harbour at Nagasaki. Nor were Japanese citizens allowed to leave Japan. Even the construction of long-range ships was illegal. These measures remained in place well into the 19th century.

But occasionally a group of Japanese citizens left Japan by mistake. Smaller ships were still permitted under sakoku since they played an indispensable role in the transportation of goods and people, and once in a while unpredictable forces of nature would drag one of these vessels away from the coast of Japan. In the autumn of 1832, for instance, a cargo-ship known as the Hojunmaru was transporting rice and porcelain to Edo (now Tokyo) when it ran into a storm and was blown off-course. The 15-metre-long ship was left far from shore without a rudder or a mast, meaning that there was no way to steer it. All that the crew could do was let their vessel drift on the ocean until they happened upon either another ship or a useful bit of land. For one of them in particular – 14-year-old Yamamoto Otokichi – this would prove to be only the beginning of a decades-long accidental circumnavigation of the globe.