Chapter six of Tomie.
A salesman arrives in a rural mountainside village. He is selling packages that he claims are seeds that will grow into a beautiful girl if planted. However, the packages contain what the villagers think is animal flesh. They call the man a con artist and chase him out of town. Before he leaves, he tips all the packages down into the waterfall.
Soon after this, young men begin to jump to their deaths from the waterfall. Two young men fishing find Tomie in the water, and assume that she is another suicide. One of them dives into the water to retrieve her body, but he doesn't return. His friend goes in after him and sees that Tomie's body is actually growing out from the rocks like a plant. He is horrified to see dozens of Tomies underwater, cannibalizing the first boy to speed up their regeneration. The second boy is pursued by a Tomie, but escapes.
The boy returns to the village and tells the people what he saw there. They find his companion's half-eaten corpse; but no trace of Tomie. Some time later, the Tomies emerge from the water and march through the village, to the horror of its inhabitants. The Tomies wander off in different directions and disappear into the night.
The salesman from the beginning may be an adult Souichi Tsujii.