Long before sushi became international food, there were only 3 different makizushi (roledl sushi) in Japan; kappa (cucumber), kanpyo, and tekka (tuna).
Kanpyo are dried gourd shavings. The gourds are mostly grown in Tochigi Prefecture and are harvested during the months of July and August. The dried shavings are hydrated by placing in lukewarm water, are then drained, and cooked in a broth (dashi) of soy sauce, sugar and sake. The cooked gourd shavings are then used as a center for the rolled sushi. Kanpyo is an excellent source of fiber.