Hirari is a human girl that was raised by the powerful Vampire of the Rikkai clan, her life going more or less smoothly. But what will happen when she discovers she has a unique power, one that could increase the power of a clan? What will Atobe, the King head of the Hyoutei clan, do, knowing he can crush his rivals of a lifetime by owning her?

Among the Yakuza of Japan, three were the strongest families. Hyoutei from Tokyo, lead by Kato Jeizu; Rikkai from Yokohama, lead by Yukimura Seiichi; and Yggdrasill from Zawame City, lead by Kureshima Takatora. They were always fighting for supremacy, until two decided to join forces against the biggest and strongest, Hyoutei…