Joerg is widely known for the high-quality dolls he makes, known as the Rosenberg Doll, which are sold for tens of thousands of mira. He takes pride in his work and only accepts job he himself is genuinely interested in. He was requested to work on the stage and lightning of the Arc en Ciel stage.
The Doll Studio is actually part of the Thirteen Factories, for which Joerg develops the foundation of weapons used by Ouroboros. He is also an old acquaintance of Renne, helping her with adjustments and repairs of Pater-Mater.
Head of the Thirteen Factories, F. Novartis, considers Joerg peerless when it comes to fine-tuning and making the final adjustments to dolls, whether they are consumer collectables or humanoid weapons. He had Joerg do the final check on the Aion.
Despite Novartis' praise of Joerg's work, their working relationship is strained. Joerg loathes Novartis' way of working. When he was still working on the Pater-Mater, Doctor Novartis confiscated the machine and had it sync with a still very young Renne. Especially since Novartis knew the risks of his decision, Joerg considers him inhuman.
Around S.1207, Joerg received a strange request by a client to create a special doll. Combining both the prowess of his doll-making and the Society's technology, he created a doll that was capable of expressing emotions and movement. The client had told him to leave the doll in a trunk near the Temple of the Moon.
Joerg was later called away for an unknown purpose, which resulted in Novartis taking custody of the workshop and modifying its interior. Before he did so, he contacted Renne and asked her to help the doll he had created when the time was right.
Zero and Ao no Kiseki
- Imelda calls him an 'obstinate gramps'.
- Crossbell Archive, p.257.