Error 404 with unicode character in the URL like Japanese

Hi,

I want to allow Unicode character in the URL like Japanese.

I added in my route.php

$route['category/(:any)'] = 'Category/view/$1';

When I tried access "category/大人っぽすぎる小学生が中学３年生にもなると.html", it's ok. However with the string "category/筧美和子さんのニットの衣装が素晴らしすぎる.html", it failed and return 404 error (please refer this image https://imgur.com/8lCA7s4 )

I don't know why and how to fix it. Please help me, many thanks,