The wartime imprisonment of Nikkei on Indigenous lands has been recognized as having produced a double displacement under the auspices of American settler colonialism. Less clearly understood are the forms of postwar political awareness that this displacement provoked in Nikkei inmates, especially those who were children or teenagers at the time. One determining factor in our lack of understanding is the fact that mass incarceration, like the mistreatment of Indigenous peoples before, alongside, and after it, obliviated much of the historical record. However, while the fragmentation of memory, both individual and shared, has been a hallmark of Nikkei experience in the US, it also has been a spur to political action, even alliance. This article addresses efforts at unearthing the memory of imprisonment on Indigenous lands. Its aim is to begin accounting for the longer-term impacts of contact between groups that imprisonment generated. That contact matters, not only because it defies the white settler-colonialist narrative of the time, but also because it has begun to generate important, if nascent and complex, intergroup alliances.