Yuyaka

Yuyaka (also known as Yuyangga, Yuyaka-sairo and Yuyaka-kousai, Kanoshi: ゆやか) is a semi-mythical figure of Kayokan legend, known as a sairo or 'knight' under the first Emperor, Hizai Tayamoto. It is said that he accomplished many amazing and borderline supernatural feats, including but not limited to: In addition, Yuyaka was said to have psychic abilities, along with supreme intelligence and strength which made him almost invincible in battle. According to folktale, Yuyaka's final accomplishment was discovering how to live forever. He lived on as an ageless spirit, and disappeared into the Shidomo Mountains, never to be seen again by any mortal being.
 * swimming the Sunrise Strait in a raft made from oak leaves
 * climbing Mount Makaza with only the clothes on his back
 * battling and defeating the Dragon of Hoku
 * eating lit coals and breathing fire
 * inventing a castle which could walk of its own accord
 * hunting three hundred deer in just one day
 * freezing water into ice with his own cold breath

Some sources say that Yuyaka may have been based on the real sairo Korugai, who worked for Emperor Hizai near the end of his life.