Please try Japanese popular snacks if you come to Japan, they are all easy to buy at super markets or convenience stores. Here are the recommendations; they are Top 5 snacks in Japan on one TV show here. You can trust me! (The price can be a little different with stores.)
According to the TV show, there are 3 categories in this election; snacks, cookies, and chocolates, and they were elected by 10,000 Japanese people. Here are the Top 5 snacks, here we go.
Rank 5, Jagarico Salad Potato Stick (salad flavor) by Calbee.
60g, JPY135.
After Jagarico came to Japanese markets in 1995, it became so popular in Japan. They are very crunchy potato sticks and there are also other flavors, here are the flavor of salad, potato with butter, and cheese from the left. I like them very much, too.
Rank 4, Chip Star by Yamazaki Nabisco. Simple and light taste. Chip Star is once mashed and then baked, so the shape of the chips are all the same. 50g, JPY98. 
Rank 3, Curls, cheese taste by Meiji. 72g, JPY105. Very airy and crunchy puffed corn chips. All Japanese kids like Curl. There is even a song of Curl. 
Rank 2, Potato Chips, green laver with salt by Koikeya. 60g, JPY98. Koikeya uses potatoes made in Japan and put Japanese seasoning on the chips, green laver flavor. This chips taste of sea with flakes of seaweed.
And Top 1 snack in Japan is Kakino Tane by Kameda, 38g x 6 mini packs included, JPY198. Kaki means a persimmon and Tane means a seed in Japan. Don't they look like persimmon seeds? These are crackers made from rice. Roasted peanuts are also packed with. Very good with beer!
Why Japanese rice crackers with peanuts? It is said that the origin of the combination with crackers and peanuts is from Imperial Hotel Tokyo. The waiter at the bar of the hotel had served peanuts for foreign people, but one day he added the crackers so that the snack can be more Japanese taste. Kameda Company started to sell crackers with peanuts in 1966. Popular with guys.
If you have a chance to come to Japan, please try one of them, and also take it to your home as a souvenir.
Please also check Top 5 Japanese Chocolate Confectionery - Chocolate Election!
Please also check Top 5 Japanese Chocolate Confectionery - Chocolate Election!
Experience Japan!