Thanks to effigy for his input I figured it out.
For all those having trouble I did this:
According to the website which contains all the Japanese Unicode Lib.
http://www.rikai.com/library/kanjitables/kanji_codes.unicode.shtml
//convert japanese characters
$url = mb_convert_kana($url, "asKHV");
//remove all symbols
//table provided at http://www.rikai.com/library/kanjitables/kanji_codes.unicode.shtml
$pattern = '/[^\wぁ-ゔァ-ヺー\x{4E00}-\x{9FAF}_\-]+/u';
$url = preg_replace($pattern, '+', $url);
Just in case anyone ever needs to do this.
The function will convert all the characters first using the mb_convert_kanahttp://php.net/mb_kana_convert function then will remove all Japanese Symbols and only leave Hiragana, Katakana and Kanji.
Hope this helps anyone having this problem.