Second the other reply. I have been in Japan for 4 years. I will say less than 1% may be able to communicate in English, less than 5% may be able to string together words in English to help you with some common stuff, less than 10% may utter some words in English.

But same is true, in reverse, for western foreigners living in Japan. Very few are able to communicate in Japanese.

It's true. 50% may know a few words, but probably less than 5% speak good enough English to have a regular conversation about something more complex than the weather. You can definitely live in Tokyo without knowing Japanese and do everything you need to do, but your options, socially and otherwise, are always going to be limited.