Yasha-ou is first seen when he arrives late to a court session where it was learned Kuyo, a stargazer, had escaped her 300 year captivity for refusing to serve the new emperor. Taishakuten ordered him to find and kill her, despite the knowledge Yasha-ou and Kuyo were friends. While he accepted the orders, he did not verbally agree to carry them out. Instead, he did go searching for her, as he knew where she was instinctively. He found her in a ruined temple, waiting for him. She had a message to give him; a promise that she'd made to Ashura-ou as his last will.
'Six stars wander and fall... Though shalt find a child and foster him thyself.
he shalt be the key to your destiny. The six stars shall unite...
There is one who shalt descent to the house of Darkness.
One who shalt govern the orbit of the stars.
The blaze of the red lotus thou rear'st shall burn away all evil.
The six stars shall be opposed by all, but dominated by none.
And the six stars shall be the break which destroys Heaven.'
It was her last act, though Yasha-ou left before he allowed himself to accept it. He left her alive, promising to return with the child of the prophecy and hope to get further aid in figuring out what more he had to do. Even with the knowledge that very child he was to foster was destined to kill him.
Having learned where the child was, thanks to Kuyo, Yasha-ou went off, unafraid and resolve firm. If Ashura-ou wanted it of him, he would do. Rather, he was eager to meet the child. No one had been able to enter the forest the child was kept in in three hundred years. Rumors said it was protected by a demon. However, Yasha-ou's sword, Yama-to, protected him and allowed him simple passage past trees and to his target.
When he freed the child from the tree, a strange spirit of darkness addressed him. Demanding to know who he was. Without letting him answer, he was informed that by awakening the child, the forest would no longer protect the world from him. Even knowing the destiny of the child, Yasha took the babe from the woods back to his clan for temporary shelter that would give him time to return to Kuyo.