I know nothing about database but I think I’ve found a solution.
Go to phpmyadmin (in your cpanel) and see your database. Then maybe you will find out that the collation for your database is ‘swedish… something‘. That’s why your WordPress front end won’t show Japanese characters.
And then change all the collation to “utf8_general_ci” or something like that. Don’t ask me how to do it, I just clicked around and find some button to change the collation of each files (or folders, not sure).
