Pronunciation of Japanese "j"

I was rereading Mark Rosenfelder's article on chance ressemblances between
words in different languages, and was suprise to see Japanese "j" (in
_gaijin_, specifically) described as a "dental affricate" - presumeably [dz_d]
or [dD]. Other sources give postalveolar [dZ] or even palatal [J\j\]. Anyone
nipponically enlightened out there feeling like telling me what's right?

                                                                  Andreas

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