This thesis explores conversion to Christianity in contemporary Japan. Christianity is widely regarded as having failed to make any impact on Japanese culture, and to be a foreign body (indeed in the opinion of some an irritating foreign body) that has failed to accommodate with or indigenise itself in Japan. And yet, Japanese people continue to choose to convert to Christianity. What is the significance of this? Are people who convert those who feel excluded from mainline Japanese society, the proof of which is their affiliation with a foreign religion, or can this phenomenon of conversion be understood in a different way? This thesis suggests that it can be, and that the fact that small but significant numbers of Japanese regularly convert to Christianity means that the understanding of Christianity's place in the Japanese religious landscape needs to be re-examined.Theories of conversion are studied, with a view to identifying the particular approaches to analysing and understanding conversion which will be appropriate for the Japanese context. The work of Rodney Stark and William Bainbridge on conversion to a deviant perspective forms the starting point for the study. Cultural and religious norms of Japan are identified, with a view to investigating in what ways and to what degree Christianity in Japan represents a deviant perspective. The history of Christianity in Japan is studied, indicating that at certain times in Japan's history when there is a feeling of national uncertainty and of a lack of social integration there is an openness to Christianity, although at times of national self-confidence there is more resistance to it. Christianity is also compared and contrasted with Japan's New Religious Movements, which may also represent a deviant perspective. Qualitative research among converts to Christianity is carried out. The results of this research show that while there are parallels between conversion to Christianity and to New Religious Movements there are also areas of difference, especially in terms of motives for conversion. Motives for conversion to Christianity tend to focus on what might be termed 'the spiritual', and conversion is experienced in terms of emotional peace, welcome into a Christian congregation, and the promise of salvation to come, rather than the 'health and wealth' or 'this worldly benefits' which are reckoned to be, or to have been, motives for conversion to New Religious Movements. As Shimazono Susumu points out, however, the so called 'New' New Religions also have a focus on spiritual salvation.The conclusion reached is that, though Japanese who convert to Christianity are choosing 'the other' in that their choice is clearly not to stay within the religious mainstream of the country, yet Japanese society is more heterogeneous than is often assumed and actually embraces a range of diverse groups. Christian converts, while being aware of the tensions which they face as a result of conversion, do not feel 'outsiders' in Japanese society. So, while Christianity cannot be said to have indigenised in the way that Buddhism clearly has, yet it should not be seen as an unsuccessful foreign import, but rather, in terms of glocalisation, as a culturally appropriate local expression of a global movement.