It seems that `tr' in GNU coreutils does not recoginize multibyte
character, but other imprementation, e.g. HP-UX, Solaris, recoginizes it.

As a result, [ echo AB | LC_ALL=ja_JP.eucJP tr AB '\244\263' ] is
transformed as [ echo AB | LC_ALL=ja_JP.eucJP tr A '\244\263' ], so that
'\244\263' is recognized as a single multibyte character.  We do not
expect that.