Nintendo sold more than 230,000 New 3DS and New 3DS XL during the handhelds' first two days on sale in Japan.
The hardware revision was launched alongside 3DS-exclusive Monster Hunter 4G, which itself sold 1.6m copies.
The amount of interest in the 3DS XL was probably skewed due to it being available in a bundle with Monster Hunter 4G.
Both handheld designs feature a new C-button for dual analogue controls, something Monster Hunter 4G takes advantage of.
Improved 3D viewing, built-in NFC capability and a beefier CPU are also included.
There's no word yet on a European release for the devices, other than a vague promise of "2015" from Nintendo UK.
"From the outside, the new design appears very much like the old - same size, same shape. But looks are deceiving - you'll notice the difference from the first moment you pick it up," Eurogamer's Tom Phillips (hello!) wrote in our recent New 3DS XL hands-on.
"The New 3DS XL is considerably lighter than the existing model and thus much more comfortable to hold."