Thanks Tom, that is also excellent advice!
I do need to talk to to them more about payment, as it wasn't totally clear yesterday. It doesn't help that his English is about as poor as my Japanese, but the designer will also come along, and her English is much better, so I'm thinking of writing everything down and hacking that out fairly near the beginning of the session.
The label deals with mainly Techno music artists, although I think on Monday we'll be doing at least one track with rap vocals. I'm very comfortable with most electronic music mastering, as I'm an electronic musician myself, so it's somewhat of a speciality.
Looking forward to it!