Whoever you are, hopefully you've already connected your 3DS to the eShop so you're actually registered for your games
Which means your 3DS must be online, thus you must post your friend code!
http://board8.wikia.com/wiki/Nintendo_3DS_Friend_Codes
GuessMyUserName (Gmun) 3737-9524-7626
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Miyamoto: [cats] are kind of like girls. If they come and talk to you it's great. But if you try to talk to them it doesn't always go so well