I'll first be covering food items that aren't desserts. The items in this list can be easily found at festivals and are sold by street vendors around Japan. You can also make these items at home if you have time.
These are just dumplings filled with pork, but it does fill you up if you're in a rush. You can sometimes buy these with some dipping sauce if you wish. Dumplings are very convenient if you plan on walking around since they aren't very messy.
These are pancakes that are filled with thick cut bacon and topped with sauce and Japanese mayonnaise. There are various other toppings that you can add to this as well like eggs or bacon crisps. In Japan people usually make okonomiyaki with leftovers from the night before.
3. Takoyaki and Ikayaki
These are squid dishes, so if you don't like squishy things I would avoid these. Ikayak is simply grilled squid on a skewer and yes it's the whole squid. There may also be vendors that offer to deep fry the squid if you're looking for a little crunch.
Takoyaki is when the squid or octopus is cut up and is cooked into a pancake that is shaped into a ball. These are topped with mayonnaise, ginger, nori and fermented fish flakes
This literally means burned chicken...but it's good! Chicken is put on a bamboo or metal skewer and then grilled over a charcoal fire. The chicken is seasoned with either tare sauce (a thick, sweet version of soy sauce) or salt.
5. Tomorokoshi and Jaga Bata
Tomorokoshi is grilled corn on a stick. Corn is grilled with miso and topped with butter and soy sauce. This is usually a quick snack and won't really fill you up.
Jaga Bata is a peeled baked potato with butter on top. You can also add Japanese mayonnaise and other sauces if it's too bland. This is a good treat on a cold day, and you can also eat it with another food item like tomorokoshi!
These have recently become popular in the west so you may already be familiar with these. Crepes are thin pancakes filled with anything from fruit to nutella and can be topped with whip cream, caramel, ice cream, or even a combination of all three!
This is truly a unique Japanese treat. These are thick and fluffy fish shaped pancakes filled with custard, chocolate or cheese.
3. Mochi and Daifuku
Mochi is simply a thick cake like substance made from mochi rice. Mochi can be toasted and topped with sweet kinako. Daifuku is mochi filled with various ingredients like red bean or machi paste. Daifuku is commonly frozen and eat