While trying to figure out these prefixes and suffixes in the nomenclature thread (http://www.jnsforum.com/community/topic/667-kuha-saha-moha-kiha-japanese-rail-car-nomenclature/page-3?do=findComment&comment=152634), I came across these pictures of a ReTe12000 JNR refrigerator car by Adachi. I see Mark has mentioned the manufacturer before, but otherwise there isn't much, so...
http://poppo.plala.jp/new_page_682.htm
http://www.jmra.gr.jp/adachi/
Now, what does Te mean...