This paper discusses the year 1905 as an educational watershed in colonial Vietnam. It focuses on the development of student mobility that transcended colonial and imperial boundaries and gave new momentum to educational training on a transnational scale. In the mid-1900s, the anti-colonial mandarin Phan Bội Châu launched a new nationalist movement called Đông Du, meaning ‘Going East.’ It centred on sending young men to Japan via Hong Kong to train them as effective anti-French activists. These students came from Tonkin, Annam, and Cochinchina and enrolled in a variety of curricula. Although this initiative collapsed in the late 1900s, it remained a watershed. Regional mobility did not disappear afterwards but mostly redirected itself towards China. This paper brings a great diversity of material face-to-face, including governmental archives and biographies, and challenges the colonial-based vision of Vietnamese education by highlighting its regional dimension, from the early twentieth century to the outset of the Second World War.