Japan Working Visa Catch 22

I made the following video for those interested in coming to Japan to work as teachers. There is sometimes a frustrating Catch 22 situation for those seeking work in Japan. In order to get a working via for Japan, you need a company to hire you and sponsor your visa. The problem is, many companies say that in order for them to hire you, you must already have a valid visa.

How do you get that visa in the first place?