Shindo Kai, hailed as an ace attorney, boasts an unbeatable record of winning countless lawsuits, but there is more than meets the surface. Lurking in the shadows, Kai operates as a vigilante assassin, punishing those who commit crimes and evade justice through legal loopholes. But this isn’t Kai’s only secret: he was born as the illegitimate child of yakuza leader Gondo Heihachiro. Although Kai has managed to keep his origins hidden while maintaining an unbreakable streak at work, things are about to change. When a new crime group known as Mayhem lead an attack on his father, a young yakuza subordinate named Kito makes contact around a time Kai also loses his first case. Upon re-examination, he discovers Chief Kasai sullied his hands, having forged and discarded crucial evidence. Who laid the groundwork for this betrayal? The inescapable story of blood begins…!