Sausage on a stick (Frankfurt フランクフルト)
Frankfurt sausage is not Japanese food, however, it is almost always sold at Japanese outdoor events or festivals. It is a smoked pork sausage, which is grilled and sold on a stick.
Takoyaki is a ball of dough with octopus tentacles inside. It is often served in a small basket with a thick sauce, mayonnaise and bonito flakes. It is eaten with a stick and is served piping hot!
Yakisoba is stir-fried noodles, usually made with thinly sliced carrots, cabbage, green bell pepper and pork. They normally serve it in a plastic container and is quite a hearty portion so it'll fill you up for pretty cheap.
Yakitori is grilled chicken on a skewer which can be eaten simply with salt or with a kind of soy sauce. Normally, when eaten at a restaurant, you would order many different types of skewers with a few beers. But at a festival, you can order one or two then move on to other tasty street food!
Grilled Corn 焼きとうもろこし
This is also a very popular Japanese street food. I dare you to walk by and not be tempted by the sweet smell of grilled corn on the cob. It is often served with soy sauce and butter and really brings out a sweet, yet umami-filled taste. It's much healthier than the other street food options and children love it.
Choco Banana チョコバナナ
Now, for the sweets!
Choco banana is basically a chocolate covered bananas on a stick, commonly eaten at summer festivals in Japan. It can be covered in milk, white or strawberry chocolate and is often very colourful and kawaii.
Kakigori is the Japanese term for shaved ice, and it is a must-eat dessert for the summer season! It's refreshing and sweet and perfect when you don't really have an appetite during this summer heat! It is served with sweet, different flavoured syrup, such as matcha, watermelon, etc.
Taiyaki is a classic dessert you must try in Japan. It is often sold in stands, and it smells heavenly as you walk by. Taiyaki are sweets shaped as a fish ("tai") often filled with red bean paste or cream. There are a multitude of seasonal variations to try as well, such as sweet potato, or chestnut.
Baby Castella カステラ
Castella is a popular Japanese sponge cake, and this is the bite-sized version that can often be found sold by street vendors. Castella is said to be of Portuguese origin and was brought in by the Portuguese merchants in the 16th century.
Crepes are really popular at street fairs, and are a staple in Harajuku! They are usually served in a thin crepe with ice cream, whipped cream, and many other toppings to choose from! There are even savoury versions. The best place to eat them is by far Harajuku, but they're great at street fairs too!