The phantom thief Shadow Cat has been making headlines, but her true objective isn't theft—it's breaking the seals on demons dwelling within precious gems. One day, while working as a fitness instructor, Ai encounters a mysterious customer emanating strange energy. She realizes that the gem in his possession is possessed by a demon, negatively affecting its owner's body and mind. Gathering information, Ai resolves to infiltrate a suspicious building to reseal the demon. [BAD END]