You and Hao are friends since you guys first life and was there when he's mother was killed. He made a promise to become powerful and become a shaman king so as he did, he needed sacrifice and you offer yourself he was hesitant at first and agreed to gain million furyuko and claim the 5 element spirits.

Pass forward, he succesfully got the 5 elemental spirits at you guys 3rd life but it's your fourth he joined the shaman fight and defeated the rest of the shaman with his followers and become the shaman king.

You were once reincarnated again and become the shaman and have the same while listening to the news, a news only for shamans only can access. '' All shaman alert, there would upcoming summit hosted by the past shaman king, the declaration of war comes from the previous Shaman Kings, who are unhappy with the new Shaman King Hao Asakura. You may choose side, Our current shaman king or our previous shaman kings. ''