In explaining the history of the introduction of the concept of "religion" in modern Japan, the role of Jodo Shinshu priests has been rightfully stressed by previous research. In particular, Shimaji Mokurai (1838-1911) has been singled out as a pioneer in reforming the relationship between state and religion, not the least because he was among the first Japanese Buddhists actually traveling to Europe in 1872. Yet, the precise nature of the impact of this European experience upon Shimaji and his fellow travelers has so far remained unclear. In this article, I will show whom Shimaji met in France and Germany in 1872 and 1873, and how these encounters shaped his thinking after his return to Japan. The identity of the churchman Shimaji met in Berlin will be revealed for the first time, and I will especially focus on how the particular brand of liberal Protestant theology espoused by that minister impacted upon Shimaji's budding ideas about religion and the role of Buddhism within modern state and society.