The two had very few interactions with each other until Rido attacked the school. After Yuki asks him to protect the academy, Aidou helps to protect Yori from hungry vampires. Since he rescued her, Yori stood up for him when he revealed he was a vampire to the Day Class students. During the extra chapter, Aidou blushes when people compliment Yori on how pretty she has become and states that they shouldn't say such things to her. At Yori's funeral, Aidou has his hand on one of Yori's grandchildren. He laments that he is sad that he couldn't have invented the vampire cure sooner and how he was awed by her fierceness in staying human when he asked to change her into a vampire repeatedly. Yori had stated that she had lived a good life but it was time for her to go. It is implied that they had gotten together.