Small (about .5 oz./14 grams) bags of potato chips, potato snacks, vegetable snacks, and ramen snacks sold in long perforated strings.
A few weeks back, Marvo from the Impulsive Buy mentioned in comments that salted snack bag sizes in Japan are usually big, and the fact that he hadn't seen any individual serving size bags of things like potato chips from Japan. By and large, this is true. In the U.S., you find small 1 oz. bags which are designed to be thrown in a lunch bag. Since the Japanese don't have chips and sandwiches for lunch, you don't find those types of bags for sale very often.
Various snacks in small bags, again, in long strings with perforations. From left: shrimp salted snacks, Calpis marshmallows, Doraemon candies (can't see the type), Anpanman fruit candies, caramel corn, Meiji's nature themed cookies (shaped like trees, mushrooms, etc.) in various flavors, gummi candies, fruit-flavored pressed powder pellet type candies (like Sweetarts).
What you do find on occasion are these long strings of perforated bags designed for children to snack on. They are smaller than the standard 1 oz. bags that you find back home, usually containing about half the volume of a standard snack size bag in the U.S. Sometimes these strings are all of the same type of snack and sometimes they are variations on a main theme.
I don't tend to buy these because I really don't need 4 or 5 little bags of the same snack, but they are handy if you want to sample a lot of different things in small quantities. I just haven't run across a sampler string that really appeals to me.