The surface of Lake Tazawa seen in fine weather is sparkling and the blue color is totally different! It was a very beautiful lake! And the Tatsuko statue was even more golden than I had imagined!

Lake Tazawa is the deepest lake in Japan, located in Senboku City, Akita Prefecture. It is a circular lake with a depth of 423 m, a circumference of 20 km, and a diameter of 6 km. Even in midwinter, the surface of the lake never freezes over. There is a folk tale of the birth of Lake Tazawa, the “Legend of Tatsuko”.

A golden statue of “Tatsuko,” the heroine of the legend, stands by the lakeside on the western shore.

According to the “Legend of Tatsuko,” a beautiful girl named Tatsuko began to wish to retain her eternal beauty when she herself became aware of her beauty.

Tatsuko secretly prayed to Kannon (Goddess of Mercy) for 100 days and 100 nights. Then, on the night of her full wish, Kannon told her the location of the spring of immortality.

As Kannon (Goddess of Mercy) had predicted, when Tatsuko drank the water from the sacred spring, she suddenly became very thirsty, and no matter how much water she drank, her thirst was not quenched.

After a while, Tatsuko changed into the form of a dragon. Realizing her own retribution, Tatsuko expanded the spring to create a lake and lived as the master of the lake. This is a folk tale passed down in Lake Tazawa. Gozano-ishi Shrine is located on the northern shore of Lake Tazawa, where Tatsuko is said to have drunk water from the sacred spring.

Tatsuko’s mother came to the lake out of concern for her daughter. She kept shouting Tatsuko’s name while holding the torch, and a dragon appeared from the surface of the lake.  When the mother realized that her daughter had become a dragon, she said goodbye and threw the torch into the lake. When the torch entered the water, it turned into a fish and swam away. This is said to be the origin of the “kunimasu trout” of Lake Tazawa.

Kunimasu trout is an endemic species that inhabited only Lake Tazawa, and is a freshwater fish of the Salmonidae family of the order Salmonidae that was once thought to be extinct. According to “The Legend of Tatsuko”, the kunimasu trout was transformed from a torch, so it is also called Kinoshirimasu trout. Kinoshiri means the bottom of the torch tree. In 1940, Tamagawa River water was drawn into Lake Tazawa in order to increase grain production and develop power, because the Tamagawa River was highly acidic, Kunimasu trout became extinct.

Between 1995 to 1998, the Lake Tazawa Tourist Association offered a reward of 5 million yen for the discovery of kunimasu trout, but it was not found at that time. However, in 2010, kunimasu trout was discovered in Lake Saiko (Yamanashi Prefecture) at the foot of Mt.Fuji by ichthyologist Sakana-kun and Professor Tetsuji Nakabo of Kyoto University.

Kunimasu trout eggs sent from Lake Tazawa to Lake Saiko in 1935 are thought to have been bred repeatedly to reach the present day. Kunimasu trout breeding is exhibited at the “Lake Tazawa Kunimasu Museum (Kunimasu Miraikan)” on the shores of Lake Tazawa.

Lake Tazawa does not freeze even in midwinter. According to the “Legend of the Three Lakes” passed down in Aomori, Iwate, and Akita Prefectures, it is said that during the winter, “Hachiro Taro,” the dragon god of Hachirogata Lagoon, comes to meet “Tatsuko,” the dragon god of Lake Tazawa, and that Hachiro Lagoon without its master freezes and Lake Tazawa does not freeze even in winter.