When you start getting into what Japanese refer to as "O-tsumami", generally meaning snacks to have with alcohol, you start getting into some pretty strange food. But if you like these kinds of food, it isn't so strange at all.
One notorious snack that turns many people away but others inhale, is called "shio-kara". This stuff is basically like pudding, except it isn't sweet. It's ground up squid guts and everything in a sort of thick paste which makes it possible to scoop up with chopsticks. It is a bit spicy, and provides just the right balance of salty flavor when drinking bitter alcohol.
For first-timers, this may not be for you! But if you're willing to try it, then you may just become a fan!