C³: C Cube [Portuguese]

Yachi Haruaki is a high school boy who is naturally resistant to curses. After his father sends him a mysterious black cube, Haruaki awakes to find a nude girl named Fear standing in his kitchen. She's the human form of the cursed black cube - and an instrument of torture! Utilizing her special abilities, Fear fights alongside Haruaki to defeat other cursed instruments and their owners.