Anko bean paste is a popular filling for Japanese sweets.
Tempura is battered fried veggies, fish and meat.
Udon noodles are a very popular snack food.
Takoyaki are fried octopus balls, which are a common and very yummy snack food.
Mochi is a chewy rice ball, extremely common and delicious.
Dango is a Japanese dumpling related to mochi, but doesn't taste as good (personal opinion)
Matcha is a fine and expensive type of Japanese green tea.
I'm missing Japan now