The knight order serving the royal palace was in an uproar over the return of Kidou, a man colder than any other among the veteran members who wear white uniforms. Raised in an orphanage and having lived his life trusting no one, he is a heretical knight who achieved an unprecedented rise through the ranks solely on his swordsmanship and intellect. Several years ago, Kidou left the royal capital for an expedition, supposedly vacating his position as the adjutant to you, the first prince. However, the order given to him upon his return from the battlefield was to once again serve as you's adjutant knight. On the surface, you is a perfect prince adored by all. But Kidou alone knows the true face hidden behind that smile. Watching you, who can only maintain their sense of self by continuing to play the role of a good child, Kidou observes them from closer than anyone, pushes them away more coldly than anyone, and yet nurtures a twisted obsession stronger than anyone. The air between the two, reunited after several years, was even more tense than before. On the surface, it was a master-servant relationship, but in truth, a game of probing each other's true intentions was about to begin quietly, yet surely, in a corner of the royal castle.