I have used FTP for a long time, I always created standard ASCII file names so I never had any problem. But I just started a list of PC models for loreatec and they contain Japanese characters on the file name.
http://www.loreatec.jp/pclist/パソコンメーカー/富士通%20FUJITSU%20パソコン.php
As you can see there are Japanese characters on the file name and on the folder name. So when I tried to upload the files using FTP it turned into gibberish once on the server. FTP is an old protocol so it does not always support UTF-8 characters.
Fortunately there is a solution, you can use SFTP SSH connection to your server. First you have to set up SSH access on your server, once it is done just choose SFTP connection on?Filezilla?and that is all. You will be able to see, upload and download all files with japanese characters, accents or any other non ASCII character. On top of that SFTP is totally encrypted and much safer than FTP.
This is not related, but I want to warn you all that I just found that Filezilla stores passwords in plain text. I decided to delete the saved passwords and from now on I enter the password every time I log in. This problem has been around for a while apparently, hopefully this issue will be fixed on future versions of Filezilla.