From what I get in your professional experience, I believe you should be able to find English speaking jobs in Japan.
I believe you would be required to have a certain level of Japanese - the JLPT N1 certification is the best bet but normally N2 is required for the decent office jobs like yours. But anyway, if you have not done so, please start learning Japanese immediately. Becoming a business fluent in Japanese is not an easy but not impossible with the right strategies (on Italki, you can find a plenty of resources on this matter).
And you need to find the Japanese company that is willing to help you get a work permit in Japan - you could search for jobs on Jobbatical (in there most of the jobs come with a visa-support).