The Sino-Soviet Friendship Association (SSFA) was China's largest mass organisation of the 1950s. Whether it was marking events on the socialist calendar, showing films, holding lectures, or arranging worker competitions, the SSFA had an inescapable presence in public life. Invariably, the Soviet Union was presented as China's benevolent 'elder brother,' guiding it to modernity. By taking part in SSFA activities, Chinese were interpellated into a discourse that legitimated communist rule and defined their nation, world, and future. Yet, even within such a top-down, closed discursive system, there remained room for the inquisitive to form authentic friendships with their foreign Other. In addition to examining internal documents and public activities of the Shanghai and Beijing branches of the SSFA, this essay covers three rounds of pen-pal exchanges between Lu Shuqin and 'Natasha,' young women workers from Beijing and Moscow. Rather than adhering to the expected inner-socialist bloc hierarchy, their letters reveal an egalitarian cosmopolitanism. When read against China's state-sponsored narrative of 'elder' and 'younger' brother, these pen-pal letters complicate and expand the discourse of Sino-Soviet friendship, showing how the mandated internationalism of the 1950s interacted with the self-directed behaviours of socialist individuals.