This article explores relations between transcultural processes and historical boundaries. Drawing on the Deleuzo-Guattarian concept of assemblage, it examines the selection and organisation of cultural elements in a Japanese-styled Chinese New Year installation at a Hong Kong shopping mall. The article presents three affective regimes produced in this transcultural assemblage: New Year festivity, simulated tourism, and partial historicity. We argue that these regimes are regulated in the processes of erasure (the selective blockage of competing lineages of rituals, traditions, and spaces) and forgetting (the process evoking creative re-organisation of semiotic boundaries between cultural elements selected into the transcultural assemblage). This article suggests two implications. First, transculturality is not only the dialogic transgression and creation of boundaries but also the selection and regulation of cultural elements in an assemblage. Second, historical boundaries are not sidestepped but are regulated by the partial blockage through erasure and re-organisation through forgetting in affective regimes. (Transculturality, assemblage, affective regime, erasure, forgetting, Hong Kong)