Jimmy Gibbler is Kimmy Gibbler's younger brother (in Fuller House). He was looking for her at the Tanner household when he came across Stephanie playing a song on her guitar. Jimmy liked the song and sat down to visit with her. They kissed, and then Kimmy saw them. Stephanie was stunned when Jimmy did the Gibbler gallops with Kimmy, and that is when Kimmy revealed that Jimmy was her younger brother. Stephanie was shocked and horrified that she had kissed a Gibbler.
At D.J.'s super fun barbecue party, Kimmy asked Jimmy to pretend to be D.J.'s boyfriend, but Jimmy had a hard time keeping up the facade because he had feelings for Stephanie. Stephanie initially rejected Jimmy, but she eventually gave Jimmy a chance, and went on a date with him in his trailer where she didn't mind being, despite the fact that she thought he was going to take her to a fancy restaurant. Stephanie finally faced the fact that she had feelings for Jimmy, despite the fact that he was related to Kimmy.
Their relationship hit a small roadblock when Jimmy was offered a job in Auckland, New Zealand (though he kept confusing Auckland with Oakland), and also mentioned that he loved her, which overwhelmed Stephanie and caused her to avoid him. Jimmy surprised Stephanie when he showed up on Christmas, having decided he wanted to be with Stephanie more.