Itsue Aasu, the fifth of seven sisters, bears a name derived from the Japanese word for "five." This 19-year-old balances high school with a part-time job as a dominatrix. Her profession bleeds into her personality, making her quick to administer physical punishment with her whip when angered, especially towards her sisters. She possesses distinctive neck-length purple hair and matching purple eyes.

Her primary magical ability is the "Earth Barrier Shield," acknowledged as the most functional defensive power among the Aasu sisters. She channels this power through her whip, spinning it overhead to generate a protective energy dome. Within the family home, she participates in traditions like communal baths. Itsue exhibits a blunt, domineering attitude, exemplified by her tendency to blame household disturbances on her younger sister's menstrual cycle.