Althrough born a merchant's son, Yazen was gifted with spiritual strenght. He joined the Dangaishu after being spotted by a traveling monk.
One day, Yazen went on a punitive expedition against the youko Kuzunoha. But he fell in love after seeing her under the moonlight.
After joining forces with Kuzunoha, Yazen used the spiritual awakening and killed every man from the expedition.
