Billionaire Tono Ryuichi, the President of Tono Foods Group, a giant food company, recently acquired two young female assassins from the Mexican cartel. Sui and Ai came from unimaginably poor childhoods and was given a choice between killing people or selling their body. They chose the former and went through an inconceivably extreme training and, at 17 years old, they have become one of the deadliest assassins in the world. They are absolutely obedient to their master and they are given the task of finding the killer that poisoned Ryuichi's wife and child. They begin attending high school to blend into society and, at the same time, read and study which helps them become even more deadlier on the field. Sui and Ai encounter Matoba Imari who is a high school assassin herself and may be more skilled than both of them. But unlike the two, Imari just wants to lead a normal life. Whatever Imari wishes for her life is not their problem because the only thing Sui and Ai feeds on are bloodthirst and a challenge.

Appears in the Black Lagoon art book Black Lagoon: The Book of Venom. It is a crossover between Jormungand and Black Lagoon. Revy meets a young Koko Hekmatyar who offers to sell her weapons.

Shiragaki Seiya, a high school student and the daughter of a mangaka, is anxious to become financially independent so as to relieve the burden on her single mother. One day while on the way to school, she has an encounter with "The Spirit of the Chest, Aurelia de Medici," and thereafter finds herself thrown headfirst into a no-holds-barred otherworldly battle revolving around money.