With the support of Kyushu based trader Thomas Blake Glover, arrangements are made through his local agent, a Mr. Weigal, to secure passage for the five students on one of the many British trading ships calling at the port of Yokohama.

The Chōshū students disguised as English sailors are put aboard the Jardine, Matheson & Co. vessel Chelswick for a thousand ryō each with the reluctant agreement of the ship's captain, J. S. Gower.

The five depart Yokohama on June 27, 1863, bound for Shanghai where they will be sheltered on an opium storage ship before dividing into two groups for the extended voyage around the Cape of Good Hope to London.

While Inoue Masaru, Yamao Yōzō and Endō Kinsuke travel to Europe as passengers on the 915 ton three-masted tea clipper Whiteadder, Inoue Kaoru and Itō Hirobumi, destined to be two of the greatest Japanese statesmen of the age, are mistakenly assumed to be eager to earn their passage as crew and are put to work as deckhands on a grueling one hundred and thirty-day day journey aboard the 525 ton sailing ship Pegasus.

The Satsuma domain has become closer to the British, despite the bombardment of Kagoshima in 1863, and is pursuing the modernization of its army and navy with their support.

The Scottish dealer Thomas Blake Glover sells quantities of warships and guns to the southern domains.

American and British military experts, usually former officers, may have been directly involved in this military effort.

The British ambassador Harry Smith Parkes supported the anti-Shogunate forces in a drive to establish a legitimate, unified Imperial rule in Japan, and to counter French influence with the Shogunate.

During this period, southern Japanese leaders such as Saigō Takamori of Satsuma, or ...

...Itō Hirobumi and Inoue Kaoru of Chōshū cultivate personal connections with British diplomats, notably Ernest Mason Satow.

The Shogunate also is preparing for further conflict by modernizing its forces.

In line with Parkes' designs, the British, heretofore the Shogunate's primary partner, prove reluctant to provide assistance.

The Tokugawa thus comes to rely mainly on French expertise, comforted by the military prestige of Napoleon III at this time, acquired through his successes in the Crimean War and the War of Italy.

The Shogunate takes major steps towards the construction of a modern and powerful military: a navy with a core of eight steam warships has been built over several years and is already the strongest in Asia.

In 1865, Japan's first modern naval arsenal is built in Yokosuka by the French engineer Léonce Verny.