in japan, it is very important to follow specific instructions to master the tradition of eating sushi. otherwise, you’ll end up being turned into sushi yourself.
yes, the rules are strict. but after all, that’s the samurai way (“naruhodo, samurai no kuni desu ne”).
in my high school, there was an after-school sushi ceremony club （寿司道 = “sushido”), where we trained carefully in the art of eating sushi under our sushi-master, Kinpachi-sensei. students who didn’t follow his directions exactly were sliced carefully into sashimi with his katana sword.
outside of the formal sushi ceremony, the rules are more relaxed, especially for foreigners. but there are still many subtle cultural nuances that everyone who eats sushi should be aware of. luckily, there is now a video demonstrating (in japanese with english subtitles) the way for everyone to eat sushi.