Kyoko Zeppelin Sohryu (惣流・キョウコ・ツェッペリン, "Sōryū Kyōko Tsepperin"), Asuka's mother, was a key scientist in the German division of Gehirn (what would later become NERV's Third Branch) and the development of Unit-02, the first Production Type (the second and third of which were later produced by the two American branches of NERV). She was the subject of the Contact Experiment with Unit-02, but during the experiment her soul bonded with the EVA, causing severe mental damage to Kyoko. She became mentally unstable, believing that one of Asuka's dolls was her daughter rather than Asuka. She was admitted to a mental institution shortly after the experiment. Her husband entered an affair with Kyoko's own doctor, which eventually prompted Kyoko's suicide in 2005.