Aya Kureha works as a maid within the Twilight Mansion, serving the Giou Clan. She is the younger sister of Fuyutoki Kureha, who works at the clan's main residence, resulting in their rare meetings. Her duties involve overseeing daily household operations and supporting the residents, including the Zweilt guardians. She diligently prepares tea, a skill taught by her brother, and aids Tachibana, the residence manager, in keeping watch on the guardians, especially when they try to follow Yuki Giou without permission. She possesses black hair and olive eyes, typically dressed in traditional attire, most often a red kimono. She was also seen once in a maid outfit, a gift from Ria Otonashi. Shy and polite by nature, she addresses the Zweilt guardians formally. Aya shares a notably close and trusting bond with Touko Murasame, frequently spending time together in activities like shared baths and conversations, partly due to being one of the few females at the residence. Initially addressing Yuki Giou as "Yuki-sama" per clan custom, she promptly adopted "Yuki-san" after he expressed discomfort with the honorific, demonstrating her adaptability. Aya possesses no supernatural powers; she contributes through steadfast domestic support, striving to fulfill essential duties within the household.