Candied sweet potato. 大学芋。
Sweet potatoes are deep-fried, cut into pieces and then sugar coated. It is a calorie rich snack, developed in modern times. The name means "university potato," and dates from the first half of the 20th c. when this snack was popular in college towns as it was cheap and filled the stomach. Today, you can buy it in supermarkets, but it also appears in stands at the many university festivals that color the Japanese autumn.
[Daigaku-imo. Photo Ad Blankestijn]