Rin was once a normal highschool student. Until one day, while trying to protect a girl who was being attack by another witch, she was hit with very harmful magic. She later woke up in Elizabeths house and found out she was now an undead skeleton. She and Elizabeth not try to find a way to turn her back to normal. While also protecting the city against the recent witch attacks.

After becoming a skeleton, Rin became (understandably) uncomfortable with how she looked and tries to hide her appearance as much as possible. But other than that she's just a regular, slightly nerdy teenager. When someone she cares about is in danger she tends to spring into action without thinking (like when she saved Elizabeth)

As a magical girl, Rin can transform at will. The transformation gives her increased strength and speed.She can also summon a large scythe to fight with. It can shoot magical shock waves.