Nagashi-somen, or "flowing noodles," is a bizarre food tradition for a country as obsessed with hygiene as Japan.
A sort of primitive forerunner to kaiten (conveyor belt) sushi, nagashi-somen is a summertime cold noodle dish that is served in an unusual way: Boiled in a pot, then dumped in clumps into a long bamboo track filled with flowing spring water to cool the noodles. The track flows, like a Hot Wheels course, throughout the entire restaurant.
Diners along the route stick their chopsticks into the track to capture a batch, that they then transfer to their individual cup or bowl of broth.
I just don't know how, from a hygiene perspective, you could be happy being the last guy at the end of the track, eating only whatever noodles slipped through other peoples' chopsticks.