Recently acquiring the services of two Mexican cartel assassins, Sui and Ai, Tono Ryuichi, billionaire and President of Tono Foods Group, had enlisted their help to find the culprit responsible for his wife and child's murder. These skilled assassins grew up in dire poverty, facing the choice between prostitution or becoming killers. Opting for the latter, Sui and Ai underwent intensive training, shaping them into two of the world's most deadly assassins by the age of seventeen. Following their master's orders without question, they enrolled in high school to avoid any suspicion, studying tirelessly to hone their lethal skills whilst blending seamlessly into society. During their time there, they met Matoba Imari, another assassin with a desire for a normal life - though Sui and Ai relished in their love for killing and accepted every challenge that came their way, unfazed by Imari's aspirations.
