So i recently got my friend to send me a 3ds from japan. he used a ds himself when he was learning japanese and he suggested zelda and animal crossing games. basically go for the games targeted at younger audiences because they tend to be more beginner friendly. so far i have gotten though 1/4th the opening cut scene because i keep looking up words... this will take practice. i'm going to pick up the animal crossing game とびだせ どうぶつの森 soon i think, that or majora's mask. leaning towards the animal crossing game just because i think it might have less cut scenes and be a little easier. i can figure out about two words of the six words on the screen before it's on the next screen.
also just for anyone thinking of buying one the nintendo shop is currently restricted by the region of your console/handheld, and some of the handhelds went region restricted i understand. i spent alot of time trying to figure out how to buy one so as far as price goes.
1)friend send it 2)i didn't check the handling costs thoroughly but probably tenso.com 3)then playasia, nipponyasai, amiami (heard good and really bad things of a couple of these) 4)something else to check is for a specialty store in a large city near you, i found out about my 3ds was sent there is a store in seattle for instance with a ds for 79 bucks.
all in all it cost me 120 dollars with shipping for my 3ds, good luck with your language goals.