According to the tale, a school containing thousands of of golden koi swam up the Yellow River. The fish gained strength by swimming against the current. At one point, they reached a waterfall and the majority became discouraged. They turned back finding it much easier go with the flow of the river.
360 Koi refused to give up. Leaping from the depths of the river, they flung their bodies into the air repeatedly, only to fall back into the water. Their movements attracted the attention of malicious demons who laughed at their efforts and raised the height of the falls. The Koi were undeterred. For 100 years, they continued on. At last, one heroic Koi leaped and reached the top of the falls. For his persistence, the Gods transformed him into a dragon.
The falls have become known as the Dragon's Gate, and for their perseverance, Koi have become symbolic of overcoming adversity and fulfilling one's destiny.