Once upon a time, world was thrown into a chaos by people from another world with special powers known as “The Lost Ones”. To maintain peace, “The Executioners” are to kill “The Lost Ones” without mercy. This is a story of an unlikely pair; executioner Menou, who tries to be pure, honest, and strong to carry out her mission and “The Lost One” Akari who has extraordinary ability. Where will the path lead them?