If I buy a Japanese 3DS, and play pokemon on it, will those pokemon count as foreign for the masuda method?

Does the 3DS need to be assigned to a Japanese location? Does the game need to be Japanese?

Studying abroad in Japan in a semester or so and was planning on getting a Jap 3ds while there to practice my moonrunes. Just curious if I could also use it to make my own masuda mons.