One of my more adventurous half hours involved trying to find a 3 to 2 prong adapter at the giant Yamada store in Sendai, where virtually no one spoke enough English to figure out what I needed and my limited Japanese did not include "adapter." Eventually, they dragged a young lady over from another department who sent me up to the 6th floor (yup, big store) where I found a whole wall of different electrical adapters. Only took another 5-10 minutes of searching but I left the place victorious. That store was one of the most intimidating places I have been in Japan.