"Kings" are beings who have received extraordinary mystical abilities and the power to enlist others into their lineages. Safeguarding the wellbeing and dignity of their kin is a core responsibility for these rulers. When a clip showing the brutal slaying of a Red Clan member goes viral, the unsuspecting pupil Yashiro Isana is charged with murder. Consequently, a pursuit for his capture begins, drawing him into contact with the notorious "Black Dog" Kurou Yatogami—a master swordsman and fighter pledged to honor the directives of his deceased mentor, the Seventh King.
At the same time, the present Red King Mikoto Suou confronts an impending death as Yashiro"s investigation tightens. Yet while Yashiro fights to clear his name, a deeper plot unfolds; hazy memories surface, and close companions begin doubting his very reality. What started as a lone killing now escalates into an all‑out clash among Kings, threatening the world"s destiny. The escalating conflict threatens not only the Kings but also the balance of all realms, urging alliances betrayals to surface.