Deep within the Forest of Okoya, a tribe of Zarude lives at the Heart Tree and its surrounding healing springs. The Zarude reign over the jungle, regularly terrorizing other wild Pokémon and stealing their food. One day, after collecting stolen food, one of the Zarude hears crying and discovers a human infant in a cradle on the riverbank. Unable to let the child perish in the wild, the Zarude brings him back to the Heart Tree, incurring the wrath of the others as the law of the Zarude prohibits outsiders from entering the area. The Zarude decides to leave his tribe and go into exile to raise the boy, giving him the name Koko and being dubbed "Dada" by him in turn. Ten years later, Ash Ketchum visits the Forest of Okoya from nearby Milyfa Town. While attempting to capture a wild Cramorant, Ash and Pikachu encounter a research team from the Biotope Company, a scientific organization studying the jungle. Team Rocket, covertly following them, look up information on the Biotope Company and its leader Dr. Zed, and decide to infiltrate the group. They soon find that Dr. Zed is looking for a legendary power source deep in the jungle where the Zarude live, and he doesn't want anything to stand in his way of obtaining it, even the Zarude who have the job of protecting the jungle and its ecosystem. Released Christmas Day 2020 in Japan followed by Netflix streaming, then DVD in the US in 2021.