Oranguru lives in the forest near
Mallow house on Melemele Island in the Alola Region. Just around the time that
Abe opened the Aina Cafeteria, he was in the forest and zoned out and ended up getting lost. He tripped and fell down a hill and injured himself. Oranguru not only nursed him back to health, but also listened to his problems and served him a delicious Pile Juice. Word about the "master" as
Abe calls him eventually spread to the city and they all worked together to build the café so that islanders wanting to soothe their souls could come there.
Mallow ran into the forest one day after getting mad with her father and tripped an fell down the hill in a similar manner injuring her knee. She met Oranguru and it treated her injury and also listened to her problems while serving her Pile Juice which she recognized as tasting similar to the one that her father served in his restaurant.
When Team Rocket showed up and had captured
Mallow's Steenee, it showed that it was a highly intelligent Pokémon that has skillful command of manmade tools. It used its the fan-like object consisting of layers of leaves bound together with its own fur to fight against them and managed to rescue
Mallow's Steenee.