Kaon Lanchester is first introduced when Sougo unexpectedly bump into her in episode 1. She was trying to escape from Roman and Otto from trying on her wedding dress, for, Roman and Kaon herself were going to get marry, which was arranged by their parents.   

In Episode 12, she later becomes "Kaon Valoff" after she got married to Roman Valoff. She is also the mother of two daughters & one baby child.