History of Reikaigoku Jidai

After the end of the Genpei War, the newly crowned shogun Minamoto Yoritomo declared the need for a mortal power that could fight back the spirits when they threatened Japan. Under the guise of executing his cousin Minamoto Yoshinaka and other relatives, the shogun secreted them away to several mountains throughout the land to begin searching for a way to meld the powers of spirits with the autonomy of humanity. Though the details of their studies are lost to time, the Kaminoha of modern day are the end result.