Blacktooth at one point was a Ninefang warrior. He was once the son of the tribal chief of Blacktooth tribe. The Blacktooth tribe found a secluded valley a large amount of naturally grown millet rice. This prompted another powerful tribe, the Blood Mosquito tribe to surprise attack them and destroy the Blacktooth tribe. Blacktooth lost lot of his tribal brothers and one of his daughter. He fled along with his other daughter Spring Grass. After fleeing all the way to the Ji clan Western Prefecture City, Blacktooth sells his daughter Spring Grass to the Ji Clan in order for her to have a better life as he decided he would walk in the path of revenge. Eventually the Blood Mosquito tribe is destroyed and the surviving members joined different clan. After his revenge he became a successful travelling merchant and rebuilt the Blacktooth tribe and also found out where of Spring Grass lives.
Blacktooth comes to the Ji clan and talks to Ji Ning about getting back Spring Grass. He narrates his life story to Ji Ning and successfully convinces him to give back Spring Grass. He then brings Spring Grass to his new Blacktooth tribe.
Blacktooth is next seen when Ji Ning visits the Blacktooth tribe to visit Spring Grass. He lies to Ji Ning and tells him that Spring Grass married a travelling merchant and gives Ning a letter from Spring Grass. Ning then reads the later and afterwards confronts Blacktooth about his lies. Blacktooth then takes Ning to the graveyard of Spring Grass. Afterwards Blacktooth tells Ning the truth about Spring Grass and how she was abused by River He and that she committed suicide through poison and that before her death she wrote a letter to Ning about marrying a travelling merchant so that Ning would only remember the happy Spring Grass.