Sometimes, website will check 'reference'. That is, what website were you on when you clicked the link. In this case, it's neogaf. You clicked on a famitsu link while on a neogaf page so "neogaf.com" was then passed as the reference.
Websites do this to avoid unnecessary traffic. Famitsu gains nothing from serving any audience other than Japan.
Gaf don't buy their magazine, they gain nothing from ads from gaf users, gaf is not applicable to their promos/campaigns, and gaf (probably) don't understand Japanese. And gaf don't buy Japanese games regularly either.
Normally, sites don't need to do this since the traffic would be negligible, but gaf is very big.
In Firefox, you don't even need to copy and paste. Just press enter on the URL bar after you get the 403.