This article argues that there is no single relationship between Japanese Buddhism and Ireland, but rather a series of changing relationships mediated by different world-system contexts between one island and another (peripheral and post-colonial) one: as ethnographic information, as cultural influence and as religious practice. The process has a long history, stretching back to the Irish reception of Jesuit and traveller’s accounts, and then made concrete by early intermediaries like Lafcadio Hearn / Koizumi Yakumo and Charles Pfoundes. WB Yeats helped to give Japanese Buddhism a significant place in Irish culture, notably in poetry. From the 1960s and 1970s Japanese Buddhists started to settle in Ireland and Japanese Buddhism began to be practiced; both are now an established part of the Irish religious landscape. The article sketches this history together with the present situation of Japanese Buddhism in Ireland.