The 124-kilometer Niyodo River is the purest in all of Japan. It possesses a striking hue of blue known as Niyodo Blue that is a testament to the cleanliness of its waters, which have remained pristine despite serving the needs of 100,000 locals. The program vividly portrays the Niyodo through gorgeous photography captured with the latest technology and Masakatsu Takagi's evocative piano score. The Niyodo remains blue from the forests that give it birth to its mouth. Along the way, its waters nurture the colorful wildlife that live in and around the river while also displaying a surprising expressiveness themselves. These aspects are filmed in meticulous detail with the help of guide Nobuyuki Takahashi, a photographer with intimate knowledge of the river.