It is explained in the story that Elizabeth is a ghost of a young girl who was once a member of a noble family during the Holy Roman Empire. Elizabeth is first introduced in the third episode when she "moves in" to Kazuki's dorm room. She once lived in an old mansion that was located between the girls and boys dorms until a group of real-estate agents from the Kazetsubaki group drove her out. After Kazuki and Yuna make an unsuccessful attempt to retrieve a suit of armor for her, Elizabeth creates a magical vortex which sucks Yuna in. Elizabeth threatened to torture her so Kazuki uses his magic to save Yuna, who ended up being tickled instead of tortured. Kazuki's magic resulted in the girls dormitory being pulled toward and merging into the boys dorm.
When Elizabeth sees Kuriko, who resembles Elizabeth's mother, lift up a helmet, it reminded her of a knight that guarded her and Elizabeth adopts Kuriko as her new mother. From then on, Elizabeth lives in Kuriko's chest and often tries to help Kuriko with Kazuki. When Kazuki becomes a ghost at the midpoint of the story, Elizabeth tries to gives him advice in order to cheer him up. She also seems to get mad easily, and then starts to use her magic to destroy things in anguish.