It's very hard to scalp xbox series x in Japan, aside from the times amazon jp gets stock (amazon isn't tracked by famitsu btw, so it's not included on these 100k ;) ), stock is only sold in physical stores, 1 purchase by person (and you can't buy both the S and X), using a special credit card.
Series S was also like this until late September, but they open up now (and it's appearing on several online stores).. but series S isn't supply constrained in most of the world, makes little sense to scalp to outside Japan.
Ps5 is different, usually gets big drops online, and in way bigger numbers than Microsoft ever shipped.