Hey there again,
Yes, the reference literature for the B7000 is only available in Japanese - reason being is that the B7000 is a JDM-only tractor. Kubota decided not to make an "equivalent" model for the North American or world-wide market. Thus, there is no other parts manual to use in place of a parts manual for the B7000.
That being said, it is still possible to use a parts manual that is written in Japanese - many owners of gray models like yours do seek out original parts manuals or literature. The reason you can still use a parts manual that is not written in a langugage you understand is because the parts diagrams reference parts by English numbers which are then cross-referenced to the part number/description chart below.
Once you have those part numbers it's as simple as picking up the phone and placing an order with your local dealership. I would neglect to mention that you have a gray market Kubota - dealers are bound by their agreement with Kubota Canada/USA to deny service to these types of tractors. They risk losing their franchise/dealership license if they knowing help you with your gray market tractor. You can see the "situation" they get themselves into if you tell them about your wonderful JDM Kubota... they want to help you because they want to sell parts and maybe build a relationship with you, but if they do and get caught, head office will lay the hammer down.
Will Kubota eventually relax their stance on gray market models? Maybe. Maybe in 75 years when all those gray models are sold for scrap and turned into new Toyotas!
RE: Location of serial number - for the B7000 I do not remember at the moment. I'll ask Vic to post and also check our stash for that parts manual.