Haruka Hasebe is a teenage girl with waist-length blue hair, orange eyes, and a mole beneath her left eye. She is considered highly attractive, with a well-endowed figure, but she is not very open to others. She prefers to keep to herself and avoid trouble, yet she speaks freely and teases those she trusts, like her friends in the Ayanokōji Group. She nicknames her close companions, such as calling Kiyotaka Ayanokōji 'Kiyopon' or 'Ayanon'. Despite her playful side, she is overly-conscious of her large bust and tends to avoid flirty boys. Her uniform is worn with the top button undone and her tie loosened.