In the Mythological Creatures Research Centre, the creatures and demons are divided into five color bands: red, orange, yellow, green, and blue. Red was peaceful, orange was defensive, yellow was hostile, green was dangerous, and blue? So hazardous that one swipe, slash, bite, or sting could kill instantly. Shiro is a rookie red-level guard, but she longs to be the captain of the blue bands. When a blue-level Blackstone dragon, Théo, is severely injured, Shiro jumps at the chance to help him heal his wounds. Shiro’s affection and gentle attitude towards him touch his heart, and the dragon grows fond of her. Shiro too grows to adore the magnificent dragon. When a fire rider from the blue bands escapes, the chaos is major, as fire riders can kill anyone they touch. As the citizens start to disappear, Shiro is tasked to find the fire rider, as she is special, since she and Théo share such a close bond, and no one has ever even come close to taming a yellow-band creature, let alone a blue-band one.  Shiro is afraid, and Théo can’t leave the research center, so he can’t stay with her to protect her, like he normally does when any creature at the center attempts to attack her, and there is someone following her everywhere. Can she find the stalker and the fire rider?