ID please - Japanese Knotweed-like plant

[aspidistra]

This plant has appeared at the end of my garden - it's at least 7 feet tall and looks very like Japanese Knotweed, although I can't see any red tinge on the stems. Also the leaves are growing in direct pairs, rather than off set which is how they seem to be growing in all the pictures I've found online.

Is it Japanese Knotweed or something less scary? Do I need to move house???