[Nyororin]

Strongly religious groups, including Christianity, tend to be viewed as suspicious and cult-like.
In general, religion in Japan is more just a series of customs than beliefs. I don't know anyone who is strongly religious. Mostly it is a go-through-the-motions sort of thing. I have encountered a small handful of Christians in Japan... About half of those had "converted" because they needed to be Christian to teach in a Christian school, and the other half were of the born-again want to save your soul types.
Neither were or are common.

Please note, there is no reason to offer your opinions on religions in this thread. The question has been answered (a very long time ago, in fact) so I am closing this.