Struggling to make ends meet as a substitute teacher, Shiki Yukitaka is unexpectedly offered a lucrative deal by a mysterious woman to become an assassin for 5 million yen per kill. Reluctantly agreeing to target only the wicked, Shiki is drawn into a dangerous world as he teams up with Yan, the driver motivated by money, and Kuzumi, a vengeful cop. Their first mission takes a dark turn when they encounter the target's imprisoned daughter, Itsuki, who possesses a chilling ability. As they navigate the moral implications and the looming police investigation, Shiki must grapple with the risks of protecting Itsuki while continuing their high-paying but perilous ventures.