Have read on other threads that Japanese girl is on a lot of punter's 'to do' lists and came across this one:
In Bristol but confusingly also claims to be Asian British?
Her ethnicity reads "Asian OR Asian British", so I think she is claiming to be the former one. Also, Asian refers to East Asian (Chinese, Korean, Japanese) for most part of the world except for the UK where Asian refers to South Asian (Indian, Pakistani).
BUT that being said, most east asian girls claiming to be japanese are in fact korean or chinese... there seems to be a premium attached to japanese girls sort of like some EE girls trying to pretend to be British. So chances are she isn't japanese but you will never know as it is not like you speak japanese