Souseiseki-lapis lazuli stone
Souseiseki (Japanese: 蒼星石, German: Lapislazuli Stone) is the fourth doll of the Rozen Maiden series. She is the younger twin sister of Suiseiseki.
Souseiseki has a much smaller role in the manga than the anime, which is merely a plot device to continue the story. Her master, Kazuha Yuibishi, has been seeking revenge for the woman who eloped with his brother, which led to his death.