Takitarō: four climbers see giant fish in Lake Ōtori, Yamagata (1982)

Lake Ōtori lies at 963 metres in the Asahi range of Yamagata Prefecture, on the north side of Mount Itō. It formed behind a landslide dam. It is small, and deep. A 1959 survey measured 65 metres.

The legend came first. In 1885 the naturalist Matsumori Taneyasu recorded "the big one called Takitarō", about five shaku long, roughly 1.5 metres. In 1917 workers on a sluice gate caught two fish of about 1.5 metres and roughly 40 kg. By 1975 the manga Tsurikichi Sanpei had carried Takitarō across Japan.

19 July 1982. 6:15 in the morning, by the date Japanese Wikipedia gives. Satō Masakatsu, who ran the Asahiya inn, later remembered 17 June.

Asahi village had planned a Mount Itō climb for a tourism campaign. Only two people applied. So four climbed: the two applicants, Satō and one more. Japanese Wikipedia names the others as Iozawa Tomoya, a geomorphologist, Onodera Ichirō of the village office, and Matsuda Kenzō, a conservation campaigner.

At about 1,250 metres elevation on the mid-slope, they stopped to rest. Satō happened to look down and saw V-shaped waves moving on the lake’s west side. He raised his binoculars and saw several giant fish swimming there. Satō had known the name Takitarō since childhood. He was certain.

One fish was judged by eye at about 2 metres. Another account has a fish that size chasing a school of small fish. Later retellings grew to several dozen fish, or 3 to 4 metres. One climber drew a sketch. The story reached the front pages.

That September an echo sounder found large fish echoes, but no confirmed fish. From 1983 to 1985 Asahi village ran a full survey, with NHK taking part and Iozawa Tomoya leading. Sonar showed about 100 fish echoes between 20 and 35 metres down. An NHK Special broadcast the results, and Takitarō became known nationwide.

Two years brought little. Then, on 27 October 1985, gill nets caught a female fish. 70 cm. 5.6 kg. The experts split. An Amemasu-type Nikkō char, said one. An Amemasu close to Dolly Varden, said the other. The team ate it. "Lean, yet fatty, and very tasty," Satō recalled. The fish was stuffed and is displayed at the Takitarō-kan museum in Ōtori.

The climbers stood roughly 290 metres above the water, and sizes in the story swelled with retelling, which one Japanese writer calls typical of oral tradition. The candidates are many: a large landlocked char, stocked kokanee, the Japanese huchen, grass carp, a distinct local char. Murakami Tatsuo, director of Kamo Aquarium, suggests big char that feed on smaller char and become Takitarō.

A 72 cm fish said to be a Takitarō was caught in 2001. In September 2014 a 13-person survey, with Dr Itō Takurō of Keio University, found large echoes deep in the lake and enough oxygen to support fish. It caught nothing. No photograph or film of the 1982 fish is known. The giants of that morning remain a sketch, a memory and a name.