He did finish it pretty quick, so most likely he has SpillPassPi setup (I use it too). Just keep your 3DS in sleep mode and set it aside and it allows you to get worldwide street passes right from your home internet. When the Yo-Kai Watch puzzle was added I had finished it in 2 or 3 days. Probably could have finished it in a day but I only let it run for like an hour or two per day. http://www.spillmonkey.com/?page_id=5