Once upon a time, a certain emperor became seriously ill. He was unable to sleep at night because of a terrible noise. As soon as the sun set, a dark, black cloud came in from the East, and it settled on the roof of the palace. It was discovered that this was no cloud, but a monster with huge claws.

Night after night, this terrible dragon came, and night after night, the emperor's health grew worse. It became apparent that unless something could be done to destroy this monster, the emperor would certainly die.

The only knight brave enough to face this monster was named Yorimasa. He donned his armor, over which he wore a hunting-dress, and a ceremonial cap instead of his usual helmet. He took up his best bow and steel-tipped arrows to fight the creature.

Yorimasa killed the dragon, which was the size of a horse, with an ape's head, a tiger's body and claws, a serpent's tail, a bird's wings, and a dragon's scales.

From the very moment the creature died, the emperor's health rapidly improved. The emperor kept the scales of the dragon in his treasure house, and gave Yorimasa a sword called "the King of Lions," or Shishiwo. Later, Yorimasa married Lady Ayame, the most beautiful lady-in-waiting at the imperial court.