Nandil is an Arto, a robotic lifeform created centuries ago by humans to fight wars in their place. Brought to sentience by a mysterious object called the Lantern, Nandil has made being a Templar his life's work, wielding the powers of his soul to protect the planet the Artos have claimed and simply call Home.When a ship is shot down in the sky of Home, Nandil finds the corpse of a human among the wreckage. A human that returns to life—and seems to have the same soul as an Arto. With no memory of his past and no path for the future, the resurrected man takes the name of Sangar, and follows in Nandil's footsteps.Brotherly affection becomes something much more complicated, as Sangar fights to make their relationship romantic and human, and Nandil views this as his nature demands: a war to be won.