Jem Ysanna was a female Human Jedi trainee. A member of the Ysanna tribe from the planet Ossus, Jem was the descendant of Jedi who had survived the destruction of Ossus by the Cron Supernova. As such, Jem was Force-sensitive and used her powers as a shamaness of her tribe, led by her father, Chief Okko. In 10 ABY, Jem was encountered by the Jedi, Luke Skywalker and Kam Solusar, who had come to Ossus to search for Jedi artifacts to help in their fight against the Galactic Empire. Upon sensing Skywalker's power in the Force, Jem and her brother Rayf Ysanna asked to train with Skywalker to become Jedi Knights. After agreeing to train the siblings, Skywalker took Jem and Rayf for training and departed Ossus in his ship, Jedi Explorer.