i'm just barely starting to understand encodings and how Perl handles them, so pardon the mess. i'm not sure why but this worked for me...

$ perl -e 'print "\x30\x4b","\x00\x0a"' | iconv -f utf-16be -t utf-8 |
+ perl -MEncode=encode,decode -e '$x=<>;print encode("euc-jp",decode("
+utf8",$x))' | xxd
0000000: a4ab 0a                                  ...

$ gzcat /usr/share/i18n/charmaps/EUC-JP.gz | fgrep U304B
<U304B>     /xa4/xab     HIRAGANA LETTER KA
[download]

it looks like you need to inform Encode of the current encoding of your text somehow.