Japanese grapes are a true summer treat. Japanese table grapes are seedless and have thin skins, as elsewhere in the world, but their major characteristics are the small size (usually, table grapes are rather large) and pleasant sweetness.
These are of the type called Delaware in Japan. The grapes are almost bright red and perfectly round in form. In Japan, grapes are mainly grown in Yamanashi, Okayama, Yamagata and Nagano. August and September are the best months to buy them.