Why don't you contract to a CPA then? I wouldn't think you'd be opposed to hiring a professional for his specific skills.
I don't know who best fits these criteria in Tokyo yet but would welcome an introduction. I have a strong suspicion that I was the best qualified person in Gifu.
Hence me trudging down to the tax office a few times a year with a notebook, a stack of forms, and a highlighted copy of a National Tax Agency publication with the query "So I've got an odd one for you..."