sub test ( ¥% ) {
my ($ref) = ¥%_;
$ref->{'fuga'} = 'World';
return %$ref;
}

%hash = (
'hoge' => 'Hello',
'fuga' => 'Hello'
);

%hash2 = &test ( %hash );

print $hash2{'hoge'}, $hash2{'fuga'}, "¥n¥n";