The Monad's World is inhabited by the races of the felises, varnases and arakuns. However, in this world there are Reborns and Summoneds. And the Summoneds use the Mechanical Gods and fight the invasion of the People of Forest. They live in the Holy City of Urbanus and are subject to the priests of varnases. Priests of varnases have many secrets, including the secret of the origin of the Monad's World.
Lacrima, a felis girl, was born into a prosperous family of Court Hunters. But she does not intend to continue the family business. She is Reborn and remembers that in a past life she was ‘the happiest girl’, a vegetarian and animal activist. Lacrima, contrary to family opinion, joins the Adventurers Guild.
One day, Roni, the Priestess of the Central Temple from the sacred Urbanus and one of the last people of the Monad's World, receives a task from the priests of varnases. She must go to the city of Neris and conduct an independent investigation. In Neris, young arakuns and felises disappear without a trace, mysterious ghosts appear.
Along the way, Roni, endowed with extraordinary magical abilities, helps the team of Adventurers fight off the Monsters and gets acquainted with Lacrima. Lacrima is constantly haunted by the idea that she has already met with Roni. But where and when? After all, Roni hides his face. Roni and Adventurers travel together to Neris. What awaits them in this city? Will they solve the mystery of the disappearance of the arakuns, felises and the appearance of ghosts? Was Lacrima previously acquainted with Roni? The threads of fate intertwine in the Monad's World.