If you don't know Japanese but get the chance to live there, yes you can Live without the language. Nowadays we can use Google translation, and they have huge international community in big city in Japan, you might be no chance to use Japanese itself.
However, it'll be big FUN and more smooth to communicate with the local people and understand the culture there, if you understand the Japanese language. As most of the people there are too shy to speak English, even though they do understand it with 10 years' English education at least.
Though It takes for long time to study a new language, they have some key words to communicate. And here we gather only 100 sets of the important Japanese characters which you can see a lot in the public without the translation in English, and we are happy if it can help you for the wonderful time in Japan.