Ayu hatches in the lower reaches in autumn, spends the juvenile period in the sea. It runs up in spring and lives in the river for most of its life. Ayu disappeared from the river when the way connecting the sea and the river was closed by a dam construction during the period of high economic growth from Taisho era to the early Showa era (1926 – 1989). In 1931, volunteers from the former Wara village bought 1000 young fish from Lake Biwa and released them into Waragawa River. At that time, transportation was not well developed, and the only way to carry it was by hand. Since there was no extra oxygen provided, the water was slowly stirred with a dipper so that the Ayu in the water tub would not run out of oxygen. Until Ayu was delivered to Waragawa River. All the time and effort spent on Ayu must have been extremely harsh today. Three years later, in 1934, Waragawa Fisheries Association was established and released young fish for the first time.

In the 20’s and 30’s of Showa era, most of the caught Ayu were collected at Waragawa River Fisheries Association collection point and shipped to Tokyo markets. During the peak season, it was the second-largest source of income for farmers after sericulture. However, as the times changed, no one continues doing Ayu fishing for a living, and Ayu fishing became leisure.