Already, there are episodes with the same exact story. There's the episode with a giant foreigner who is fascinated with Japanese culture following the main characters around for whatever reason, and the Ukiyo-e artist who asks one of the main characters to be a model for his painting.
This makes me wonder what it would be like if Mushishi followed the same pattern. Now technically, Mushishi takes place in a fictional era, but the setting still looks pretty much the same. So I find myself thinking what would happen if say a ten-foot European mistakes Ginko for a ninja (because he has a Mushi pin!) and follows him around everywhere asking to be taught secret ninja techniques. Or an Ukiyo-e artist stopping Ginko in the streets and saying "Your incredible beauty has inspired me! Please give me the honor of painting your picture!"
I can only imagine Ginko going "Uh......what?" (see icon) and trying to run away. It amuses me.
EDIT: Also, I totally recognized that Mugen's voice is the same as Zoro in One Piece!
EDIT 2: ROFLOL I'm watching the South Park movie dubbed in Japanese on Youtube. XDD They're all speaking in Kansai-ben and there are subtitles. XDDD
EDIT 3: Oh man this dub is AMAZING. XD
EDIT 4: *dying of laughter*