In "Eileen Flat Screen", it is revealed that Joanne is Eileen's roommate. Joanne is shown to be ill-tempered and protective of her belongings. She goes as far as to threaten Eileen if she touches her television. When Joanne found out that Rigby moved her TV plug down to plug in Eileen's new flat screen, she got furious, and stole Eileen's TV. She also steals an old man's car to drive to a bridge, so she can throw Eileen's TV off of it.
Rigby steals her TV and follows her (with Mordecai and CJ), to the bridge. When Mordecai, Rigby, and CJ catch up to her, she is seen holding the TV above the river below the bridge. Rigby dedicates a speech about how Eileen deserves the TV, but to no avail. Joanne unsuccessfully throws the TV into the river, with Rigby catching it with his whip/rope.
When Joanne requests her TV back, the wind causes it to fall into the river. Her family inheritance's lawyer appears, calling her grandfather, much to her dismay. It is revealed that she comes from a wealthy family, and that her TV was the family heirloom, which was the first TV her family's company ever invented. The lawyer also revealed that Joanne was allowed to live her life as a normal person, as long she protected her family's heirloom, and since it was destroyed, she will no longer be able to take over the company. She will no longer be able to stay at Eileen's house, either, and is forced to go back to a wealthy lifestyle.
Joanne is a human with short, straight dark brown hair, peach skin, and black eyes. She wears a red sweater, brown pants, and white sneakers.
- Rigby secretly calls her a beast and a donkey.
- She has many pet horses.
- The ironic part is she thinks Eileen is a "no respected mooch-wad" when in reality she's the real one, as Rigby revealed that Joanne uses Eileen's hand towels to dry her butt, and ate her whole jar of peanut butter. She also wanted to destroy her TV just for just re-plugging her TV.
- Whenever somebody touches her TV, she appears at the scene, almost instantly.
- She appears to have OCD.
- Her last name, Hanatronic, is possibly a reference to the real life company, Panasonic. Which is the world's fourth-largest television manufacturer.
- Her TV is later used by Pops to watch over his friends life for the last 25 years in the afterlife.