Yeah, I assume this means there’s a lot of fraud

Probably but stats aside there certainly are a lot of very old people in Japan living near-normal lives compared to other developed countries.

After an hour in any town and I'd seen more 95+yos walking about than 10 years in Britain. And the number of times I saw 4 generations of men from one family in the bathhouse!

When there's money to be made from dead relatives, and an incentive for governments to make it look like people live beyond 100 so that they can claim superiority, yeah, that's a good recipe for massive fraud.