History
Mason finds his son with his girlfriend in the woods. The pair argue before they hear yelling and find the girl has been killed. Mason suspected it was because of the Kohonta but he withholds this from his son.
The next day, he meets the Winchesters who orders to stay away from the woods after a mysterious death.
Later on, he is found investigating in the woods where they confront him. Mason reveals details of the Kohonta and they reveal the supernatural to him, as well as reasons not to expose its existence to the public. At that point, his son calls him and states he is going to kill the monster, despite Mason pleading to him. Mason then asks the Winchesters to help save his son from the monster. He then states a silver blade can kill the Kohonta and Sam reveals one on hand.
Mason and the Winchesters fight Kohonta and after a brawl. Mason kills it with the blade.