Even as early as the Azusa Street revival, there were reports of Japanese xenolalia spoken, and Japanese pioneer converts became well-known for their Pentecostal experientialism. This chapter explores the contributions of vibrant and effective Japanese leaders to the origins, growth and maturation of Pentecostalism in Japan. Foreign and indigenous ministry programmes consolidated these early beginnings through training successful church planters, including some notable women. Congregations endured the devastation of World War ii, which saw the loss of many congregants, pastors, properties, and communities. Reconstructing Japanese Pentecostalism was then undertaken through unified rebuilding programmes of the allied occupation. Piecing together the remains of former institutions, Pentecostal leaders rallied together to encourage unified efforts. Pentecostal communities also encouraged a diversity of denominations by embracing organisations and individual missionaries expelled from Communist China. Finally, international renewal influences paved the way for contemporary expressions of worship and provided a platform for a more unified contemporary Pentecostalism in Japan. Thus, Japan is in the current state of both a realisation of plateaued growth yet with a hopeful future.