It is the traditional fishing method that uses trained cormorants to catch river fish such as sweetfish (ayu). Ukai today takes place in the summer months in about a dozen rivers across Japan. By master fisherman working from long wooden boats, ukai is practiced. About a dozen cormorants on leashes who swim alongside the boat each fisherman leads and dive under the water to catch fish by swallowing them whole. In Japan and China, historically, cormorant fishing has taken place. As a method used by the ancient Japanese in the Book of Sui, the official history of the Sui Dynasty of China, completed in 636 CE, it is described. In other countries but is currently under threat in China this technique has also been used. The fishermen tie a snare near the base of the bird's throat, to control the birds. This is to prevent the birds from swallowing larger fish, which are held in their throat, but the birds can swallow smaller fish. The fisherman brings the bird back to the boat and has the bird spit the fish up when a cormorant has caught a fish in its throat. Ukai was generously protected by local and then national governmental agencies, in ancient times, who gave the Ukai fishermen extensive authoritative control over activities on the Nagara River. For Ukai fishing Wild Japanese Cormorants are trained.

The birds are 80 to 90 cm tall and they are active migrating birds, gifted with high abilities to learn and adapt to new environments. The usho takes good care of them every day, as he will depend on the birds for his livelihood. To train the birds for fishing it takes 2 or 3 years. By cormorants Sweetfish freshly caught are highly prized delicacies. On the bodies of the fish Traces of beak marks from the birds that caught them are regarded as signs of high quality. In Japan, Cormorant fishing is currently practiced in 12 places. In Japanese texts, Cormorant fishing is referred to compile in the eighth century, and depictions of Japanese cormorant fishing were recorded in Chinese texts from the beginning of the seventh century. Cormorants in Japan are captured as they rest during migration on the cliffs of the Ishihama coast in Hitachi, Ibaraki Prefecture, and delivered to cormorant fishermen across the country by request. The name for these fishermen is Ushō, or "cormorant master." they work for the Imperial Household Agency.

. In a special pouch in the cormorant's throat to be retrieved later the fish are kept and are prevented from being swallowed by a snare around the bird's neck. To provide light for the boatmen to steer and the birds to fish by each boat carries a large fire. Ukai is held mainly as a tourist attraction these days. There are Special sightseeing cruises offers that shadow the ukai boats and allow tourists to get an up-close look at the action. Hozu River and Uji River are the other rivers where ukai is practiced. At ukai fishermen who are skilled have patronage from the emperor. Samurai warlord Oda Nobunaga took the ukai fishermen under his wing, according to the legend, conferring upon them the official position of 'usho' (Cormorant Fishing Master). In traditional costumes of straw skirts sandals and black kimono, the fishermen are dressed. Cormorants' food today, consists of the small fish that slip past the snare around their neck and into their stomach during fishing along with treats of fish after the catch is over.

In fishing, the cormorants who did not participate are fed frozen Atka mackerel. All birds now dine on this mackerel in the off-season, freeing fishermen from the need to live on the river year-round. Even in the off-season, the birds need to care for every day. With their off-time dedicated to repairing fishing boats, besides, and tackle, splitting the wood needed for the nightly fires, and making traditional clothing to wear during their fishing shows for tourists, the fishermen have no time to rest. Busy all year long caring for birds, cannot seem a very attractive profession to today's youth, being a fisherman.  All the action up-close for almost an hour at a time tourists get to watch. Generally, such cruises cost around 1,500 to 3,500 yen per person. Gifu, Gifu Prefecture, home to cormorant fishing on the Nagara River are the most famous locations, which has continued uninterrupted for the past 1,300 years. In Seki Cormorant fishing also takes place on the Nagara River, but it is called "Oze cormorant fishing".