Saying that Pokémon is particularly popular in Japan is rather like saying Mario likes to jump around on platforms occasionally — it's a cultural phenomenon in the region. The franchise doesn't do badly in the West, either, but the prominence of the brand in Japan is arguably at another level entirely.
Hype for Pokémon X & Y has certainly been building, and Japanese gamers have also been looking forward to the limited edition 3DS XL models coming to the region. Amazon Japan opened pre-orders for the systems on Saturday (10th August) at 10am, and within one hour the allocation of the golden version was sold out, with the blue model following at 7pm, just nine hours later. The retailer reportedly had around 100,000 units to sell, and will presumably be chasing more stock to pick up further orders.
These bundles are yet to be confirmed for the West, but have been loosely rumoured to arrive in some form. While coloured systems with the game pre-installed would likely sell well, these designs are particularly appealing; many fingers are undoubtedly crossed.