A squad of 14 BlackWatch Mercenaries enter the "Testament of sister new devil" household then kills the loli(Maria Naruse), the maid(Zest), the sisters(Yuki and Kurumi Nonoka), captures the Heroine(Mio Naruse), and the main character(Basara Toujou). Then they collect their contract payment of 850,000 credits( 2.1 million dollars)

This story follows a particular person named Jacob Collins that is in a well known PMC. Jacob has been task with a team and a select few of knowable characters from different worlds that includes Ryuko Matoi(kill la kill), Natsu Dragneel(Fairy tail), Mira Yurizaki(Dimension W), Jung E. Young(Goddess Kiss) and Priestess/Alice(Goblin Slayer).