If seen from the long-term perspective, the history of East Asian religions definitively lacks the conflicts of Western and Middle East traditions. The Chinese “Three Teachings” (san jiao 三教) framework supported coexistence rather than struggle and competition and, therefore, terms such as “hybridism,” “syncretism,” or “eclecticism” have always played a major role in the field of East Asia areas studies. Yet, the importance of eclecticism and thematic/social overlapping notwithstanding, it is questionable whether East Asian religions could have survived through the centuries without a consistent synchronic and diachronic effort to construct the own religious luggage and to distinguish themselves from more or less contiguous religious realms. To replace the focus on demarcation with a one-sided emphasis on the absorption of themes, practices, beliefs on the part of given religious and cultural spheres appears to be a fairly illogical approach, at least if one looks at historical evidence or the scholarly debates about the concept of alterity. Accordingly, the workshop aims to collect case studies from the East Asian realm that might help (a) to describe the features of the interreligious differentiation processes at a given point in time and (b) to map constants and changes of these processes through history.