Black Rabbit and Izayoi's relationship at first could be declared as bad due to Izayoi, in the Light Novels, groping her breast and legs when she was in shock after the battle with the Water God. She even went so far as to call him her nemesis. However, as time went by Black Rabbit's opinion changed and she shown appreciation for the boy and his power and intellect. Her opinion changed to favorable during the event of epsiode 5. When Izayoi declared that he wanted their flag to be in the stars Black Rabbit replied, "Seems romantic," and they both smiled at each other. The feelings were mutual as Izayoi's teasing of her could be seen as him holding certain affection levels for her as a friend and ally, but could also be because he thinks of her as a toy. However, when she was injured in Volume 6, Izayoi became enraged, abandoned all his principles just to get back at His Highness.