Electronics.
Buy a digital camera like I did from LAOX. It's cheaper by at least 30% if one gets a Sony or any of the Japanese brands within Japan. On this trip I bought a Sony Cybershot P50.
Laox is famous in Japan. It can be found in Akihabara in Tokyo & many other cities as well. A multi media discount store & located just 1 min walk from east exit of Sendai Station.
There's also internet access here but I didn't have time to try that. Too much to do & see in Sendai!
