|First Appearance||Legend of the Golden Witch|
|Portrayed By||Ami Koshimizu|
"No, I'm not even allowed that, I'm not even allowed a night to myself to drown my sorrows!! Who are you?! Who?! You ruined my life, and won't even let me have a new one...Just what are you to my life?!"—Rosa Ushiromiya, Alliance of the Golden Witch
Rosa Ushiromiya ((右代宮 楼座 Ushiromiya Rōza?) is Kinzo Ushiromiya's fourth and youngest child. As the youngest sibling, she is not well-respected by the rest of the Ushiromiya family and rarely speaks up at family meetings. She is a single mother to Maria Ushiromiya.
In 1967, while living on Rokkenjima, Rosa met Beatrice Ushiromiya, Kinzo's hidden child. After befriending her, Rosa offered to sneak Beatrice out of the Kuwadorian and show her the ocean. Beatrice happily agreed, however, on the way there, Beatrice slipped and fell from a cliff, dying instantly. She confessed this to Genji Ronoue, who claimed that he would handle it. Rosa feels lingering guilt for her involvement in the death, though she rarely mentions it.
Rosa is one hundred million yen in debt due to her involvement with Maria's father's business.
Rosa runs a clothing brand named "Auntie Rosa".
Rosa appears as a fair skinned woman with medium-length brown hair styled in a hime cut. She wears a long, black, double-breasted gown combined with a red skirt and a white shirt. She has the One-Winged Eagle imprinted on her cravat.
Rosa is prone to violent outbursts, especially in regards to her daughter. In particular, when Maria whines, Rosa is quick to hit her regardless of the time or place. Despite her abuse and generally neglectful disposition towards Maria, Rosa still very much loves her daughter. Rudolf describes Rosa as a "quick-to-anger mama bear" when Maria is endangered.
Rosa is shown to be talented at handicrafts as she makes Maria's Sakutarou stuffed animal and later knits a scarf for him.