When you talk about the number of bits of anonymity he has once it's been narrowed down to Kanto, shouldn't that be the male population of Kanto?

Yes, you're right - I used the total population of Kanto, not the total male population. I should probably rejigger those numbers.

EDIT: OK, I think I fixed that specific error. Fortunately, the mistake had only contaminated a few numbers... I think. Please tell me if I've accidentally introduced additional inconsistencies!

It may help to resolve the tension between the two approaches more explicitly.

I believe I did do this before your comment, in mistake 3 where I discuss what the logarithmic scale buys us.