How about an arcade in an area run by thugs or "hoods", teenage punks or something? It'd be kinda funny if there was a game of chance available and you'd every so often get challenged to play a game by one of them. If you win, they might get mad and attack you and you get yen taken if you lose since suddenly he might say it was a bet. Of course, you could try to kill him if you didn't like losing money to some punk that beat you at a video game then decided to take your hard earned yen.
As for the museum... Hm, that would be cool. How about a hired sage that is really good at identifying items from that era as well as identifying the quality of things presented to him? Of course, he could be made to respond with extreme surprise at some kid walking in with a perfect condition item from the Sengoku peroid... Heh.

Of course, he'd possibly be hard to find... somewhere in the museum, lost in his thoughts as he looks over things in the museum.
An event could happen every so often, more rare... not too often since it would kind of make it seem too overused. But, there could be something that tries to steal from the museum that the players could stop? Maybe, it could get them a reward for helping.