These oysters come from Saga in Kyushu a place rich in seafoods. In Tara on the Ariake Sea coast, in the waters of the Ariake Sea these oysters have a much richer flavor and do not shrink as much when grilled. From the beginning of season in November and are served in oyster huts serving “big and sweet non shrinking” oysters.

The Ariake Sea is a body of salt water surrounded by fukuoka, Saga, nagasaki, and kumamoto Prefectures, all of which lie on the island of Kyūshū in Japan. It is the largest bay in Kyūshū with the deepest point 50 m deep, and extreme tides exceed 4 metres. It is used for aquaculture, with nori being a major product and various species of fauna, including mudskippers, pen shells, and fiddler crabs, live in the Ariake Sea. In autumn, there is red-grass along the sea shore. But the recent years have brought increasing pollution, with resultant red tides. Isahaya Bay is a branch of the Ariake Sea. Across the Amakusa Islands lies the Yatsushiro Sea.

source: wikipedia