Am I responsible for Japanese Inheritance Tax

I posted here recently about calculating the Japanese Inheritance Tax that I will likely have to pay, and many of you provided some great assistance; however, I failed to ask the most important question… am I responsible to pay at all?

Key info:

• I am on a spouse visa
• I have lived in Japan for less than 3 years
• I have never lived in Japan in the past (other than a few-month-long student visa 20+ years ago)
• My mother (who is likely to pass in the next year) has never held Japanese residency
• None of her assets are associated with Japan

I was under the impression that my Table 2 spouse visa makes me an "unlimited taxpayer (full stop) and trumps the fact that I have lived in Japan for less than 10 of the last 15 years (re: 2017 amendment), and all accountants I have spoken with confirm this. I know Japanese accountants can be conservative in their interpretation of tax liability in such situations, and I would like to be certain.

Thank you in advance for any help clarifying.