Posted it on WTF, but I will post here as well. After confirming my information with my little brother, who has actually been to Japan for a significant period of time, I determined that Silver is eating dumplings for no real reason. If anyone has a Twitter account, just explain to him that there are vending machines selling food and drinks all over the place on the streets there.
If he doesn't like that idea, introduce him to the concept of convenience stores.
The vending machines would be better, since there is little chance of him drawing police attention like Quixote and Burger King. The store is still fine, since plenty of the stores see strange customers regularly, so unless he acts overtly threatening (and I doubt he will, this guy is pretty damn charismatic) there should be no issues.