Input (grade 7): Genma fell into the Spring of the Drowned Panda while Ranma fell into the Spring of the Drowned Girl.
Output (grade 9): The spring that Ranma fell into had a drowned girl inside before, so Ranma turned into a girl from then on whenever cold water was poured onto him. Genma fell into the spring of the panda, so he turned into a panda.