Hey there

Personally, I think it's really hard to justify what constitutes an Intermediate/Advanced level of language, depending on what or who constitutes it. For example some organisations I was planning on to do Japanese classes with had advertises "Intermediate" Japanese language classes. When I was given a copy of the cirriculum I thought it was still quite beginners/elementary level.

I would say from my own personal point of view, having an Intermediate level of language would constitute being able to understand most main points and topics when standard language is used and being able to deal with situations that you would encounter in the country. Also being able to express yourself, thoughts and ideas in a somewhat coherent manner would also be important for it.

I would say it would take someone, if they were doing non-intensive language classes (lets say 2-3 hours, one day a week) about 3 years to get to an intermediate level of language. It could possibly take someone doing self study less time than that but you would have to work ALOT harder.

Regarding the books, I can't comment on the Genki I book but can say that the Japanese for Busy People is good and also 'Remembering the Kanji'. The Japanese for Busy People would be the book my Native Japanese teacher uses for her classes.