Hi
sorry for the late answer. TL in Ubuntu 12.04 is quite old, it is from 2009!
My recommendation for TeX and Japanese typesetting is to try the TL2012 pretest where I included everything (but pmetapost and pxdvi) from the tlptexlive repository.
So please take a look at http://www.tug.org/texlive/pretest.html and give it a try, that should work better.
On my system it does:
$ platex ecmptex.tex
This is e-pTeX, Version 3.1415926-p3.3-110825-2.4 (utf8.euc) (TeX Live 2012)
restricted \write18 enabled.
entering extended mode
(./ecmptex.tex
....
《縦組モード》 [1] (./ecmptex.aux) )
Output written on ecmptex.dvi (1 page, 436 bytes).
Transcript written on ecmptex.log.
$ dvipdfmx ecmptex.dvi
ecmptex.dvi -> ecmptex.pdf
[1]
9883 bytes written
All the best
Norbert